What can done if wife doesn't want to stay together and not willing to divorce?

My wife is in touch with her ex-bf. She was planning to leave my house and stay with him. In the meantime I saw her messages and we had a long discussion. We concluded that we will leave each other. Then she left my house with all jewellery, clothes and other things that she uses. She has given a declaration (on plain white paper) in writing that she is taking all these things with her and she is not being forced by anyone to leave the house. Her father and my family members signed as witness. Its been more than a month since she left her house. Few days ago I got a call from my father in law. He was shouting at me and told me that they aren't going to allow divorce. He told his daughter will return to my house but after a uncertain period, it could be 5 months or even 5 years. I am afraid they may file various case against our family to put us in trouble and get maintenance from me. I have consulted a lawyer to get divorce. He told me its not easy to get a divorce on contest. He suggested to file a petition u/s 9 of HMA. If she doesn't come back even 1 years after passing of order, then we may file divorce petition. After suddenly my lawyer changed the strategy and he said its better to file a divorce petition right now as she has already taken away her jewellery etc. Now I don't know what is right for me. Please suggest me. What if she files 498a or other cases to harass us.