How to get her to stop borrowing my clothes?

You need to sit her down and tell her "Hey look I don't appreciate you wearing my clothes especially without asking. The least you can do is put the clothes in the hamper instead of on the floor." I'd make that trick replace all those clothes she stretched out haha. My sister and I are the same size but her bust is waaay bigger so when I wear something she just wore, it's always awkward around the chest. Or you could spray all your clothes down with signature perfume (like Harajuku Lovers) and she'll probably get sick of the smell. That's what my sister did to me. I hate that Chanel crap she sprayed :(