brother's wife harassing my father for property

Dear Sirs, My father has 4 children (2 sons and 2 daughters) . He has 2 properties, one was gifted by my grandmother and one property is self acquired. 2 years back, my younger brother died. Presently, my father and brothers' wife live in the ground floor house, and me , am the eldest son and live in the first floor. My brother's wife using abusive and filthy language towards my father and demanding property as she has become a Widow. Her parents also pressure my father. , but my father is scared and informs us that no one has abused, demand or ill treated him. When Myself and my sisters have intervened , brother's wife has complained against me and my sisters to police that we are torturing her mentally and picking fights with her. Police is also siding with her. But i have electronic voice recordings in mobile to prove that she is only causing the problem. I have informed this to local police station, but they are not ready to listen. Kindly help us to solve this problem legally!!