I'm an F-1 visa holder. I graduated from my master's in May and currently doing an OPT. Since I'm in a STEM field, I'll extend it for another 19 months next year.
My girlfriend is a J-1 visa holder without the two-year home residency requirement. She came to the States in May as an au pair and still has a few more months of her program left. The contract with her au pair agency forbids entering new contractual relationships (marriage included) while in the program.
Now, we want to marry and adjust her status from J-1 to F-2 from within the U.S. so she can quit the au pair program and still be legally allowed to stay with me throughout the duration of the OPT.
What is the proper timeframe for doing that? My concern is that when we apply for a marriage license or certificate, her au pair agency would get notified, cancel her J-1 visa, and make the whole adjustment of status impossible to go through because she'd be out of status. Any thoughts on the matter?

