Regarding Divorce

I married a girl who is an UDC in Govt office . I am a Primary Teacher by profession. It is my second marriage. It is her second marriage too. She and her family told me lie at the time of marriage that her husband died due to stroke but the reality is her husband died due to taking poison. She tortured so much that he took poison to get relief of her. After staying with me 4months she went to her house and forced me to leave my family otherwise she will not come anymore. She gave continuous threatening that time. I have informed police by G.D. that time. Her father told me that time that my daughter will no do this kind of behaviour further. So I took her . It is the incident of the October last year . Now after staying with me 1 year she is becoming arrogant and going to her house without any cause and staying for 10 to 15 days a month. I have informed her family but they support her totally . She and her family always put pressure on me. What will I do now? Please suggest.