Domestic violence/ Harassment by wife to my mother

we are from Hindu family. I have been married for almost 4 years, my mother used to live with me before marriage and still stays with me. My wife was working in other district, just about a year ago, I got her transferred to my city, that I would live a good life with staying her, but my mother is being very upset by my wife. My mother's age is about 75 years and suffering from Arthritis (pain in the joint of bones), I am spending the medicine and she cries that it would cost so much. My wife abuses every day since the morning for little things. She keeps fighting and screaming over small things. My wife threatens us that both will get jail in women Pratarana cases. Sometimes she says that she will file dowry case. Sometimes she says that I will commit suicide and send both of you to jail. While we did not take any dowry in marriage, we had spent all the cost of the wedding. Whenever, I asked to inform her father than, She throws her mobile or whatever is on her hand.