1. How old is she? Is she an adult person? You have not informed whether she got legally married or not,
2. If yes, you are required to deal with this sensitive matter very carefully,
3.If she is an adult and legally got married and also if she states before the Court or police that she is married and has willingly gone to stay with her husband, then your position will become weak legally,
4. It may not be prudent on your part to stir up the issue through police since it may not yield your desired result but spoil her reputation socially,
5. Counseling is the best course of action in such situations.