contrapuntal62

Not right away....but anytime before her I-94 expires. This could be any period of time up to 6 months (technically 1 year but that's exceedingly rare), as dictated at POE.
Edit: The petition can be filed at any point after meeting (K-1) or getting married (CR-1).

Not only does everyone get in but the original USC petitioner is on the hook the affidavit of support even if the sweet young thing gets her man here.   That is for 40 quarters of work credit and that could be life if miss sweet thing never works.  

Its good that you can go back often in the new year. You should plan on that. It's very unlikely she will be able to get a tourist visa to come to the U.S. Ghana rarely gives tourist visas in general and if they do its to older people who are more established and likely to return home.
 
There have been several articles lately showing the issue of Ghanaian receiving tourist visas and abusing the privilege by not leaving the U.S. If I remember right, the articles says of the 16,000 tourist visas issued through the Ghana embassy a year about 7,000 don't return to the country. So unfortunately people there have made it almost impossible for others. 

Actually it would be comfortable middle class life style.

Either/Or. Sometimes it is a combination of both. For some it is simply getting feet on US soil. For others it is getting a stream of income from generous donations.
 
Many in the US may not think $50 is not a lot of money to send. But if a woman can convince 10 different men a month to send it, that equals to $500. That is a great deal of money to survive on in some countries.
 

The common one we see here is get married to a USC, get GC get divorced petition your SO and everybody gets in.

This is common place to lure men in to "date them" and then swindle them for money due to some "family emergency" or just to help support her.

I know this kind of stuff goes on a lot, especially in Ghana, but every time I hear about the lengths people go to in order to get a visa it just makes me sad and angry. Its garbage like this that made it so difficult for me to get my husband here and the reason many of my friend are continuing to fight to get their partners here years after applying. It's also the reason my in-laws will never be able to get visitor visas to come here and visit. Very, very unfortunate, because there are good people in places like Ghana but people like this give the country a bad name. 

The statement you quoted is the same as what O&GForever said. Better chance of being approved for a spousal visa than a fiance visa = "That said history shows K1s are less likely to get approved in Ghana than a CR1."

You have plenty of time to decide what to do, and reevaluate each step of the way. Processing times sometimes change - back when I applied CR1 was quicker than K1.

A CR1 is more likely to be approved as long as you prepare well and have the right type of evidence. I have been on this site or at least been reading posts on it since I met my husband in 2014. I have seen plenty of people denied in Ghana....both CR1s and K1s. My husband and I are one of thoses who’s K1 was denied because of the very difficult embassy. I have also seen many succeed...especially recently. 
 
Please make sure to read through the portal and the reviews. It will give you a better understanding of the unique challenges you face simply because your fiancé is in Ghana.
 
Also take a look at my timeline and the review I wrote. I listed every piece of evidence we sent in for our CR1. What we had to send in is way more than those going through countries that are considered lower fraud. 

1. I do not take the as an insult--the ad hominem "cocky--because you do not even know me.
2. I did not mean that question sarcastically, but seriously. What I was trying to say was that there are many places (that was a site another member sent to me) that simply do not reflect Ghana reality with generalizations like " "Most immigrants from high fraud countries have a better chance of being approved for a spouse visa."
 
I was confirming to O&GForever that her personal experience, and that of the others here is way more valuable than generalizations. If I did not make that clear, mea culpa,but no need for personal attacks--I have thanked how many members so far? and I have intentionally insulted how many so far?--and to what advantage would that be for me? I think you totally misunderstood that post, and maybe others as well. I have NEVER in any post here sought to personally insult someone by calling them names. That is not me.

Thank you so much. Personally, we have agreed that our financial goal is to live off of one salary (mine) for up to the first year if needed. I can do this when the time comes, and it is not a problem as  my income will be fine. (Well of course, I cannot predict the future). In other words, we already have monthly expenditure budget agreements/understandings for rent, car payments etc. Fortunately--she is really good with numbers as I am not.
 
She speaks perfectly fine English with a most addictive and alluring African accent (not SA> just A) and was educated in English.

Yup, it's the NCLEX. That said, note that this isn't just something where she can schedule the exam, pass, and be done with it. One must first qualify for the NCLEX, which almost always involves Credential Verification (CV). This process took a few months for my now-wife (she's an RN) even with paying an extra $300 for an expedite.
Edit: It also required an application to the state's BON, which had to then grant it.
 
They may also require passing an standardized English Proficiency exam, if the classes were not in English.

Its the NCLEX exam - there are different medications, procedures, a ton of different things. 
There are NCLEX books you can take one for her to study. 

As a nurse myself, keep in mind her degree will be useless in the US. Unless she went to a US accredited nursing school she will not be eligible to sit for the boards here.  I have seen many foreign trained nurses (and physicians!) Have to start over here. 
I could not find any US accredited schools in Ghana. There are a few stating they are internationally accredited but US doesnt accept that certification.
 
If you cannot afford to travel for several months you need to look at all expenses involved in each petition, the fact that Ghana is a more difficult country to get a Visa from, and if you meet the income requirements. As you have a lot of time before you travel you have plenty of time to research pros and cons of CR1 vs K1

Having been through the Ghana embassy myself, I would highly recommend multiple trips and to stay as long as you can. I made 5 trips in 2 1/2 years in order to get my husband here. You're facing a very challenging embassy, so be prepared with plenty of good, quality evidence. I would highly recommend reading through the Ghana portal and the Consulate reviews to get a good understanding of the challenge you will be up against. 
 
Which visa path you choose is up to you. The process is shorter, but it will cost more and your fiance won't be able to work until after you're married and she receives an Employee Authorization. I've seen quite a few K1s approved recently through that embassy. That said history shows K1s are less likely to get approved in Ghana than a CR1. 
 
The CR1 will take a longer time, but she will get her greencard soon after arriving and can work immediately. 
 
Either way like I said earlier, plan to make multiple trips, collect a lot of good evidence to send in with your petition (frontloading) and prepare well. 

Spontaneous marriages do certainly happen. And couples who engage in them absolutely can get a visa. I'm just pointing out that a marriage on a first visit is a red flag in determining if a relationship or marriage is real or just for immigration benefits.
 
I suggest looking around the posts on the Ghana portal (http://www.visajourney.com/portals/index.php?country=Ghana). There's 3 posts since Thursday about denials due to suspected fraud. That should shed at least some light on what types of evidence one should have / what circumstances cause additional scrutiny.
Note that any time you see "reaffirmed", it means the visa was denied the first time (almost always due to a lack of a bona fide marriage), sent back to USCIS, then reviewed again and being sent back to the embassy for another interview.

Provide evidence at the time of filing, more/ new evidence at the NVC stage, then more/new evidence at the interview.
In short, all the evidence counts, but the more you put upfront, the more the CO will see before the interview. Ghana COs are often suspected of making a decision (or at least form a very strong opinion) before the interview, so putting the best foot forward is critical.

K-3 is obsolete so don't bother with that.
For the K-1, you can meet then file.
For a CR-1. you can met then marry and file. Generally, I would suggest a CR-1 over a K-1. The only advantage (assuming no near-adult children) is the K-1 takes a couple months less time to process. Otherwise, the CR-1 is superior in every way (cheaper, faster green card, can work and travel right away, ability to reaffirm a petition, etc.).
 
That said...getting engaged or married on the first visit is a red flag. Time spent in person is important, especially if they are from a high fraud country (not sure which country she is from).
Either way, more visits and face time during the processing is highly recommended.
 
K-1: ~8-12 months form filing to interview, on average
CR-1: ~12-16 months from filing to interview, on average.

Forget about K-3 s it’s rarely given (~38 total given last year). Either K-1 or CR-1 but decide only after going to visit her - face time is important. 
 
Which West African country is she from?