I am not an expert on this subject matter, coz im still single. But Goodsoul's story makes me aware of the possible situation after marrying a girl in Nepal while you are abroad.
This is what I would do in similar situation:
1. consult with a lawyer asap, also ask your parents to consult with a lawyer in Nepal if possible.
2. Continue talking to her and make her mad, so she will say bad things about you and your family. Record all conversations, voice call, text, fb msg everything. You will need them to prove her intension in the court. If you have enough proof, thats even better.
3. I would also hire some personal detective in Nepal ( or just some good friends) to see what she is doing recently. If she is caught cheating on you, you dont have to worry about anything.
4 Be calm and confident. You didnt do anything wrong so you are on stronger side of the fence. old says: न बिराउनु , न डराउनु !!!! Good Luck