pushbrk

I'm unsure what data is available to suggest a "reason" for any particular case to take more or less time than average. Is it possible there's some sort of extra processing or wait/queue for certain individuals based on circumstances that the OP's case meets? Yes. Is it possible (and much more likely IMO) that there is not anything more than what one would consider chance? Also yes.
 
The best thing is to try not to focus on anybody else's case. You will drive yourself crazy. This will continue all the way through naturalization.

The  above represents reading the instructions carefully, interpreting them literally and following them to the letter.  No need to read between any lines on this.  Just do exactly what a literal interpretation of the instructions tells you to do.

Your opinion has been expressed.  Not perhaps, but absolutely certainly, you have no earthly idea what difficulties...I... have experienced, OR what I understand about what's going on here.  A person's difficulties have nothing at all to do with whether an answer to a why question will be available.  The sooner they stop worrying about "why?" the less "difficult" their lives will become.

It is helpful to use the proper terminology.  There are no "Cosponsors".  Your spouse is the petitioner/sponsor.  One of her parents will be the only Joint Sponsor, and the other will provide an I-864a as a "household member".  If there are any OTHER household members, they only are "counted" in the household size.  Your wife is not counted in that household size, because she isn't immigrating and is not supported by her parents.  Even if she was living in their house, she's not part of the household size.
 
Become A students of the I-864 instructions.

Perhaps you are confused because you have not yet studied those instructions.  Download them the same place you download the forms.
 
Household relation is clear from the tax returns.  The household is those three plus you.  Unless the son is combining income with the parents, he is only "counted".  I explained this before.  Read those instructions.  Mom and Dad need to provide evidence of their US Citizenship. Usually a birth certificate for each.

It is helpful to use the proper terminology.  There are no "Cosponsors".  Your spouse is the petitioner/sponsor.  One of her parents will be the only Joint Sponsor, and the other will provide an I-864a as a "household member".  If there are any OTHER household members, they only are "counted" in the household size.  Your wife is not counted in that household size, because she isn't immigrating and is not supported by her parents.  Even if she was living in their house, she's not part of the household size.
 
Become A students of the I-864 instructions.

No harm in having a joint sponsor, but whether it's needed or not depends on the country and other factors.

Your opinion has been expressed.  Not perhaps, but absolutely certainly, you have no earthly idea what difficulties...I... have experienced, OR what I understand about what's going on here.  A person's difficulties have nothing at all to do with whether an answer to a why question will be available.  The sooner they stop worrying about "why?" the less "difficult" their lives will become.

Your opinion has been expressed.  Not perhaps, but absolutely certainly, you have no earthly idea what difficulties...I... have experienced, OR what I understand about what's going on here.  A person's difficulties have nothing at all to do with whether an answer to a why question will be available.  The sooner they stop worrying about "why?" the less "difficult" their lives will become.

It's taking so long because there is a backlog.  This is common in Montreal.  You wait.  Whether you do so patiently or not, is your choice.
 

No harm in having a joint sponsor, but whether it's needed or not depends on the country and other factors.

There is no waiting for the IV, she must prepare and submit a ds260 visa application, pay the fee, get the pc, medical,  schedule the interview,  bring everything on the document list to the interview 

4 to 6 weeks is a "proper expectation".  The files are sent in batches.  Your "someone" got lucky and was one of the last files added to the batch.

In my opinion, I don’t think you will have any issues.  You can show an ongoing marriage through chat logs etc., and you have been together at least a few times.
 
Good Luck!

Nobody can know what will be easy for any OTHER person.  We all know this based on the kinds of questions we get here every day.
 
Visa Journey has partners for a reason.  https://www.visajourney.com/partners/  Not everybody is a do it yourselfer.

I agree.  While it is certainly true that we see these reverse age differences from Nigeria, being successful in the visa process, it is usually based on the amount of time the couple has spent in person.  Time together in person, compensates for red flags.  Bear in mind that short visits, no matter how many, are not as convincing as fewer longer visits.  
 
Answers like "It happens." are examples of dodging the real question.  The question about whether marriages with a wife being 20+ years older than the husband are culturally common in Nigeria, is clearly "NO".  To say "It happens." while true, simply dodges the question.
 
Will this case and its totality of circumstances convince a Consular Officer that the relationship is bona fide?  We don't know, and can't speculate because WE don't KNOW the totality of circumstances.  Unfortunately, the case involves Nigeria, arguably the country with the highest percentage of spouse visa cases being denied based on "for immigration purposes only" in all the world.  You could argue Ghana is very close, but that doesn't change anything.
 
That a person would not marry such a "different" (age, race, religion etc. or combination of all) person within their own culture, is not sufficient for denying.  We see young asian women marrying American men 30+ years older, where they would never marry a man from their own country that is that old, and being successful in not only getting visas but also having happy lives, every day.  
 
It comes down to the individual case.  The advice I would give the OP at this point is to get real and stay real.  When that interview date comes, BE real.  No flippant answers like "It happens."  Be ready to explain to a reasonable but sceptical person just HOW they can believe your relationship is genuine, and be prepared to back it up with actual evidence.
 
It does ZERO good to provide contrived evidence just to stack some more paper in the file.  Nobody is expecting this couple to have a joint lease or bank account.  Contriving such evidence would actually HURT the case.  

Because "contrived" evidence makes you look desperate.  Creating paper evidence of things not expected from newlyweds living in separate countries seems to be.....
 
....deliberately created rather than arising naturally or spontaneously. created or arranged in a way that seems artificial and unrealistic.

I agree.  While it is certainly true that we see these reverse age differences from Nigeria, being successful in the visa process, it is usually based on the amount of time the couple has spent in person.  Time together in person, compensates for red flags.  Bear in mind that short visits, no matter how many, are not as convincing as fewer longer visits.  
 
Answers like "It happens." are examples of dodging the real question.  The question about whether marriages with a wife being 20+ years older than the husband are culturally common in Nigeria, is clearly "NO".  To say "It happens." while true, simply dodges the question.
 
Will this case and its totality of circumstances convince a Consular Officer that the relationship is bona fide?  We don't know, and can't speculate because WE don't KNOW the totality of circumstances.  Unfortunately, the case involves Nigeria, arguably the country with the highest percentage of spouse visa cases being denied based on "for immigration purposes only" in all the world.  You could argue Ghana is very close, but that doesn't change anything.
 
That a person would not marry such a "different" (age, race, religion etc. or combination of all) person within their own culture, is not sufficient for denying.  We see young asian women marrying American men 30+ years older, where they would never marry a man from their own country that is that old, and being successful in not only getting visas but also having happy lives, every day.  
 
It comes down to the individual case.  The advice I would give the OP at this point is to get real and stay real.  When that interview date comes, BE real.  No flippant answers like "It happens."  Be ready to explain to a reasonable but sceptical person just HOW they can believe your relationship is genuine, and be prepared to back it up with actual evidence.
 
It does ZERO good to provide contrived evidence just to stack some more paper in the file.  Nobody is expecting this couple to have a joint lease or bank account.  Contriving such evidence would actually HURT the case.  

I agree.  While it is certainly true that we see these reverse age differences from Nigeria, being successful in the visa process, it is usually based on the amount of time the couple has spent in person.  Time together in person, compensates for red flags.  Bear in mind that short visits, no matter how many, are not as convincing as fewer longer visits.  
 
Answers like "It happens." are examples of dodging the real question.  The question about whether marriages with a wife being 20+ years older than the husband are culturally common in Nigeria, is clearly "NO".  To say "It happens." while true, simply dodges the question.
 
Will this case and its totality of circumstances convince a Consular Officer that the relationship is bona fide?  We don't know, and can't speculate because WE don't KNOW the totality of circumstances.  Unfortunately, the case involves Nigeria, arguably the country with the highest percentage of spouse visa cases being denied based on "for immigration purposes only" in all the world.  You could argue Ghana is very close, but that doesn't change anything.
 
That a person would not marry such a "different" (age, race, religion etc. or combination of all) person within their own culture, is not sufficient for denying.  We see young asian women marrying American men 30+ years older, where they would never marry a man from their own country that is that old, and being successful in not only getting visas but also having happy lives, every day.  
 
It comes down to the individual case.  The advice I would give the OP at this point is to get real and stay real.  When that interview date comes, BE real.  No flippant answers like "It happens."  Be ready to explain to a reasonable but sceptical person just HOW they can believe your relationship is genuine, and be prepared to back it up with actual evidence.
 
It does ZERO good to provide contrived evidence just to stack some more paper in the file.  Nobody is expecting this couple to have a joint lease or bank account.  Contriving such evidence would actually HURT the case.  

Because "contrived" evidence makes you look desperate.  Creating paper evidence of things not expected from newlyweds living in separate countries seems to be.....
 
....deliberately created rather than arising naturally or spontaneously. created or arranged in a way that seems artificial and unrealistic.

I agree.  While it is certainly true that we see these reverse age differences from Nigeria, being successful in the visa process, it is usually based on the amount of time the couple has spent in person.  Time together in person, compensates for red flags.  Bear in mind that short visits, no matter how many, are not as convincing as fewer longer visits.  
 
Answers like "It happens." are examples of dodging the real question.  The question about whether marriages with a wife being 20+ years older than the husband are culturally common in Nigeria, is clearly "NO".  To say "It happens." while true, simply dodges the question.
 
Will this case and its totality of circumstances convince a Consular Officer that the relationship is bona fide?  We don't know, and can't speculate because WE don't KNOW the totality of circumstances.  Unfortunately, the case involves Nigeria, arguably the country with the highest percentage of spouse visa cases being denied based on "for immigration purposes only" in all the world.  You could argue Ghana is very close, but that doesn't change anything.
 
That a person would not marry such a "different" (age, race, religion etc. or combination of all) person within their own culture, is not sufficient for denying.  We see young asian women marrying American men 30+ years older, where they would never marry a man from their own country that is that old, and being successful in not only getting visas but also having happy lives, every day.  
 
It comes down to the individual case.  The advice I would give the OP at this point is to get real and stay real.  When that interview date comes, BE real.  No flippant answers like "It happens."  Be ready to explain to a reasonable but sceptical person just HOW they can believe your relationship is genuine, and be prepared to back it up with actual evidence.
 
It does ZERO good to provide contrived evidence just to stack some more paper in the file.  Nobody is expecting this couple to have a joint lease or bank account.  Contriving such evidence would actually HURT the case.  

Your immigration approval is unfortunately related to the questions that you are avoiding.  Your interview will be worse, and harsher, but this is a taste of what to expect.  You dodged questions that you cannot dodge if you hope to move forward with this.
 
On the issue of immigration procedures your thread was actually about your chances, not procedures.   
 
No need to tell me what happens here.  I have been here a long, long time.
 
So:  My answer, is that your chances are low unless you can straight face answer each one of those questions in such a way as to convince a professional officer that this is about your marriage no matter what happens, not about how much better off you will be after your visa is issued.

What makes Nigeria hard is that young men are known to search the internet to find a path to the US.  Even more so now that Nigeria is no longer eligible for the DV lottery.   Most of these men prey on lonely older woman, making them feel special and promising them everything they aren't getting here where youth is such a concern. Many of them barely make it to the US before take off.  The CO will tend to assume you are one of these men no matter how true your intentions.  Think long and hard on how you can convince someone that you aren't one of these men.  It is always harder to prove you are not something rather the other way around. 

Careful study and becoming an A-Student of the I-130 instructions (and all form instructions) will be critical to your ultimate success.  Your question clearly indicates you haven't even looked at those yet.  Do some homework.  You have the answer to THIS question but without doing your homework, you won't know WHAT, you don't know.

If the couple ever got married legally and lawfully, in person, anywhere, then anything before that is meaningless.  They go forward with the marriage date and marriage certificate that evidences their legal and lawful marriage, PERIOD.  Yes, proxy marriages CAN BE recognized but if they have an in person legal marriage, there is no reason to try to get the proxy marriage recognized, not even a reason to mention it.