I think, rather than keeping on taking stuff, she might be better off getting help, ie talking to someone about why she absolutely has to have these things. I don’t see how this is healthy behaviour, and if you encourage her it’s just not going to stop, and might get worse and worse. Talk to her about it. Just because she is unhappy with her life, doesn’t mean she should get every single possession she wants. It might make her happy for a short while, but not in the long run. She needs something other than material possessions to make her truly happy. If you don’t want to talk to her about this, I would get her to call a counselling hotline at least to start to resolve the problem.