Why does this girl hate me so much?

So there's a girl at school who ignores me and lectures me and leaves me out of everything. She has everything I want; I three story house, a friendly family and a really nice wardrobe. Last year we were really close, did everything together. Sleepovers, shopping, cinema etc etc. But now she never invites me shopping or to the cinema or anything like that anymore,never had any big arguments so seriously what's up with her? We still hang out in the same clique but she never really speaks to me anymore.