回复：她拿的就是永久绿卡 - 新问题来了

whether it is conditional or not, the time to file N400 is 90 days before 3 years of resident since date, NOT 3 years after marriage. Of course this requires continue marriage and living with the same USC spouse.

If the marriage is stable for, say 3 years after the resident since date, then it doesn't matter because "should the GC be approved correctly with condition", the result is the same. If divorce will happen in 2 or 3 years, it will raise questions: should the GC be approved correctly with condition, the result(decision on her current US status) would be different. Then USCIS may have actions.