Go back to Nepal. Get married. Come back with H1/H4 visa. Don't need to change passport or anything. Immigration knows when people come in here. But they won't know when they went back, unless they submit their I-94 when going back. One thing of caution is ofcourse the transit visas on the way back to Nepal. Try to avoid the countries which need transit visa....since they might put entries in your passport. Another way is continue to stay here..apply for refugee or something like that...but she will never get H4, if she applies for change of status here.......just a thought...don't know if anybody has tried this before....