Another option: Marry now, and start the spousal visa process. No adjustment of status needed. In about 2 years, he can enter the US as a Green card holder.
In my opinion, she should have just gotten on a plane and returned to the US. She is authorized to board a plane with an expired 10 year card. The worst case would have been to argue her case in immigration court.....or she could have been admitted with NO court appearance. Is her appointment in Lagos? That is the WORST consulate in the world to argue a case, imo. They are tough, and they could easily deny her case. SB-1s are not given easily anywhere. Then what is she going to do?
Good luck. Keep us informed.
I agree with @OldUser and @Edward and Jaycel. You must have filed for most recent tax year, if required (and the two previous, if required) to qualify as a sponsor.
DFW is pretty straight forward for foreign arrivals. Customs, immigration, and baggage area are all in a secure, restricted area. There is only one exit point into the public area.
It's a problem, imo. You need to make the decision easy for USCIS. They clearly don't like what you sent as supporting documentation for the I-864. The path of least resistance, imo, is to find a well-qualified joint sponsor to submit an I-864 and solid supporting evidence. You won't get another chance. I agree with @OldUser.
At this point, I would certainly get my Senator's office involved. They should be able to, at least, get a response from the consulate, as to what, if anything, can be done.
It would be helpful if you properly completed your VJ timeline so that we could see all the associated dates in your case. What is the date for the approval of the I-129F (NOA2)? When was it in "Ready" status at CEAC? It appears the consulate no longer has the case. Normally, the consulate can (and does) extend approved petitions for 4 month increments up to a year. It appears your case was at DOS longer than a year. I hope you can revive this one. Good luck
Edit: Has the US citizen contacted their US Congressperson or Senator? The message says you HAD the chance to re-instate the case, but you failed to do so.
Not possible. That is not how it works. No one is getting a Green Card or visa prior to their PD becoming current on the visa bulletin unless they qualify in a different category which IS current.. The Visa Bulletin is certainly NOT useless.
The normal process is to call the applicant and ask if they can travel prior to visa expiration date if the medical expires within a couple weeks. Sometimes, they even direct the applicant to obtain a new medical if it is close to expiration. That has been the case in multiple instances I've seen. Keep us up to date. We are rooting for you.