It looks like it's all her own hair, maybe some extensions for volume, but i think all the length is hers.  I'd be interested to see when the next album comes out if she changes or updates her look at all, as it seems most musicans reinvent themselves everytime they have a new album or come back from a hiatus.

Seeing alot of her style is in the goth realm, I think she would look interesting with some different styles,instead of the all one length look. I think she would look good actually with a bob, or inverted bob, and keep the black hair but add some pink or red strands. But something very trendy and that can be seen in Hot Topic, would go over big with her fans. I see more of the inverted bobs with black hair and her clothing styles, then the hairstyle she most recently had.