She has been betrayed and destroyed by the "mother," but there are plenty of people in the forums here that grew up fat as kids but became human as soon as they had control over their own food intake. From anecdotal evidence it sounds like that usually happens around age 15-20, depending on how abusive the parents are. She'll be stuck with health problems for the rest of her life because of what is being inflicted on her, but she can definitely drag herself back to humanity when she's a young adult.