US Immigration from Vietnam

Hello everyone. I have just sponsored my fiance to come to America. We have gone to court to get our marriage license, and also went to the social security office to apply for a SSN for her. My next step is to apply for a greencard for her. As her husband, I will be the one sponsoring her but do not meet the 125% poverty income requirements, so I will use my mom as the joint sponsor. Do I fill out the I-864 and my mom fills out the I-864A?

I currently live at home with my mom, grandmother and my mom's younger brother, and my wife. I am not sure what number I should use for household size on my I-864 application? And on Part 6 section 8, should I put my mother's name along with her current income from her latest tax return transcript?

Part 6, section 21 and 22 - I'm unsure of what to check or do here. I've attached and circle below the areas that I have questions about.

I am currently in the process of preparing to help my wife out fill out her AOS/Greencard (I-485) application along with the Work EAD Permit and Travel Docs applications and have a few concerns and questions.

1. What kind of questions do they usually ask?
2. Do both you and your spouse go in together for the interview?
3. How long is the interview process and do they have translators available if needed, my wife's english isn't good?
4. Do they require you to prove that your marriage is real by asking to see a bank account with both your names on it, monthly statements or bills with our names on it, etc?
5. I have a joint-sponsor to help me with the I-864 application, if that person is retired can they still be my joint-sponsor since I do not meet the 125% poverty income rate? My household size is 3 or 4.
6. How long does the entire process take in order for my wife to receive her greencard?

Thanks in advance!

is there example of invitation letter??? My wife want her parents come visit us and our sons for 6 months. Please advice thank.

I recently filled out the i-134 as my fianc will have her K1 interview Next month. As I was on video call with her I showed her the form so we can cross check and she mentioned Page 8, Part #4. I'm pretty sure I leave this blank as it states that portion is if she fills it out on her own behalf. She further mentions to me that people who have recently passed their K1 interview completed part 4 of the i-134. I've highlighted on the screenshot here, any thoughts?

ps: I'm thinking that if I complete part 4, I'll have to change the checkmark on page 1 that states "filing on own behalf" which is not right for our K1.

My wife is applying for her greencard (I-485), Travel Docs (I-131) and Work Permit EAD all at once. But she is stuck on Part 2 Application Type (I-131). She chose 1d so that if there's an emergency back in Vietnam such as a family health crisis or similar, she can travel to Vietnam, take care of what she needs to and be able to return back to the US without any problems. Has she chosen the correct choice? There's also a reentry permit as well. I just want to make sure before submitting the application. Also, regarding Part 3, does this need to be filled out now? She doesn't have a timeframe in mind on when she needs to travel since this all depends on if there's a family emergency, then she will know the date and time for travel, but as of now, there's no need. So can she leave part 3 blank and skip it?