I want to get full custody of my half sister
OK I'm going to be 18 in April my dad is trying to get custudy of my half 3 year old sister but I don't think he'll get her because of his back ground with drugs an so on an her mother has a really bad back ground to but the reason I want to get full custody is because 3 months ago my sisters moms boy friend beat my sister up an craked her head open an has been abuseing my sister sexual to the state has already been after her but she just moves to get away how can I get her this is something I truly want to give her a better life then what she is already leading in can some one PLEASE HELP!!