I'm probably the only one here who's a big fan of hers Her style, music and personality, though I can see why others might not like her. It took me some time to get used to her.
As for her body; as others have mentioned it seems like she is a typical natural skinny girl so she probably doesn't watch her diet or work out. If she did I think her body would be perfect. But she is still pretty thin so I can understand why she doesn't bother, however, I think it'll bite her in the butt when she gets older.
I'm only a fan of her body-haha.