Courts

Taking someone to court for refusing to move out of one's property

Q: A girl and her 7 year old son went to my mom to ask for a place to stay till she found a place to rent. On her first day she harassed and threatened my mom. She did not want to move out. Is it permissible to take court action against her. Also, what prayer or fast can I do for my mom because she is really scared and she feels that the home is in darkness.