Oh, Kristyn, I have recently lived through a very similar situation and it upsets me so badly to hear that this girl isn't being taken care of properly. I don't really know what to tell you, but if she persists in coming to your home, and the people who own her, friends or not, don't care, you might talk with your parents about permanently rehoming her.....lots of ways to do that, but the best would be for her "folks" to agree to let you help. It makes me very sad to hear this......