1. Proof of Nationality that you are Nepali Citizen
Nepali citizenship and its english translation
Passport (current or expired)
Driving License from Nepal
Birth Certificate
2. Port of Entry
I-94 (both side)
US VISA
3. Proof that you are in US on and before June 24, 2015
F2 / COS or any documents that shows your current status
Utility Bill (Telephone, GAS, Medical, Insurance etc)
Bank Transaction
Doctor Visit
Credit Card Transaction

Since you are in F2, you might need the following too
F1 I-20 from the primary candidate
F1 SEVIS
College Transcript
Relationship document between husband or spouse (if you guys are husband and wife)

Hope it works.