You can indeed have her arrested for trespassing even as family...however I would recommend going to the court house in w/e jurisdiction your in...explain the situation to the clerk of the court and ask how to begin eviction proceedings. In many states you must have a legal eviction notice served as they are family and/or resided with you past a certain # of days/months. We had to do this with my younger brother. Also you are going to need to have the locks changed.