I'm sorry to hear your are having the same issues that me right now with my SD. She is yrs and she does EXACTLY what you just describe and nothing work.. her father had talked to her and we had bought her lots of underwear and is the same thing over and over again. At this point, I'm checking her room EVERYDAY for my stuff. Since the only thing she care about right now is her friends and social media.. I told her (as the last resource) that next time I found my underwear and nasty pads in her room that I was going to post those pictures in facebook. I know it sound mean but I don't think is fair that our house stink and I have to buy new underwear every month (I do laundry every week) She have underwear of her own, clean one. But for some unknown reason she keep stealing mine. (Nothing had work for me and that is a constant fight with my husband) I really hope you have a better luck finding a solution to this problem.