Firstly, if her reason is that "You're coming to the US too soon" after you guys have waited for 3 years (as claimed by you), then she's probably with someone else over there! You need a good lawyer. Also, I'd advise you to travel to the US as sooner as possible before she blocks the move. If the fault is indeed from her and with the amount of time you've waited, then you traveling to the US should not be regarded as "an advantage" as seen from some other comments here.