eviction of a sibling

[Andre Smith]

I bought a home for my mother and father to live in. My sister moved in about 5 months ago with her children. She did not have permission from me and i did not know until today. My mother kept it a secret because she wanted to help her. She is a drug addicted and has become violent, uncontrollable and has been stealing. My mother called the police and they made her leave for the night but she was allowed to return because she has mail coming to the house and my mother is not the offical owner of the house so the police said they couldn't make her leave. I am the owner. My mother finally called me and filled me in on the situation and wants her gone! what are my fastest options?