US Immigration from Cameroon

Hello! I am new here and in the process of filing out my I-129F. I have a few questions and would greatly appreciate any help. My fianc e's father is of late and her birth certificate doesn't show his date of birth. Her mother's date of birth just states the year and that's it. Would I just write out "UNKNOWN" in the DOB field after printing the form and because her mothers' year of birth is the only known element, put "1/1/XXXX"? I don't want to misrepresent but I am unsure how to go about it. Also, she is currently a student so when it comes to employment, Will I put unemployed in all the Name of employer sections and NA in subsequent boxes or Student in one? I see some people say it is okay to put student in the Employer section. I apologize if these are redundant questions so please feel free to refer me to previous posts that contain relevant answers. Thanks in advance!

Hey all, I hope you are all doing well and having a better day than me. I was here last time concerned about my siblings being denied visa based on the new public charge and health law. My mom is the petitioner for her minor kids, after approval USCIS we submitted civil documents and financial papers. She filed form I-864 and I filed I-864A. she makes $7000 a year and I make $59000. both incomes combined come to $63000 for an household of 6 members. So today the embassy requested my mom to complete and submit form I-864EZ and W-2 form which totally excludes me from the process and they will base on her own income. Which is not even close to the $38000 required by the poverty guidelines for 5 persons. I don't know if anyone has been in this situation before or have any advises please share your experience. I'm completely lost.

I need helps from those who received Documentarily Qualified Notice from NVC in F2A visa category in Cameroon. I received my notice on June 26, 2019 and I am still waiting for Interview Letter. I would like to know how long it takes for Green Card holder to Get appointment for interview in Cameroon. I called the NVC on November 26, 2019 and they said they cannot guest and it is almost 6 months now. I would also like to know if someone knows an example of inquiry I can put in. I am from Cameroon and the interview will takes place at Yaounde Cameroon. Thank you for your help.