Legal advice on family tensions

We are 3 brothers living in same house on separate floors with our mother. My younger brother's wife for absolutely no known reason is trying to create problems here. She is completely after my mother trying new ways to instigate her. We have moved in here about 4 months ago and she has started torturing my 13 year old son by destroying his things he plays with. Everyone here is afraid of her as she threatens that she would get all in family into jail. On top of it, because she is pregnant, no one here wants to create issue here with her. I am not sure why, but her acts are insane. I am concerned about my son as I see possibility of her harming my son. Most people here in our neighbouhood have advised me to file a complaint for harrasment. Though things are not so dirty between us brothers, I have never thought of going to such extents, but for the sake of our family I need to know my option. As laws are so bent towards women, it is easy to misuse them. Looking for your advice. Thank y