You do not have wait until the 90 day window opens if filing an I-751 waiver. You can file early.
***Moved to the Removing Conditions on Residency forum***
Sounds similar to me....and normal for a senior citizen. I am almost 73, and I see my primary care professional every 6 months just to refill my blood pressure meds (and get routine blood work done once a year). Might be difficult to expedite for being old.....
I believe the Field Office has a lot of discretion. I think I remember cases where they did the N-400 part first, but waited until after the I-751 was received and adjudicated prior to approving it.
Filing an I-485 would be foolish as it would be immediately denied. You can file an I-130. Be aware, that she will be deportable if she overstays......and she would never be able to adjust status through you as a Green card holder if she overstays.
Looks legal, but why are you doing this? Why not just get an official court house marriage which would be 100% solid? Never leave room for USCIS to question anything.
The OP is adjusting status from a K-1. No I-130 is required. My point, as @TBoneTX stated, was that a person who enters the US via a spousal visa can work immediately.
Great report. One thing you can do now is to schedule a passport appointment for some point after the oath (if you can schedule that far out). That saved us a lot of time for wife's passport as appointments were very hard to get in early 2023. Congratulations......it is a great feeling being out of the pressure of USCIS.