I like this, and I dig the tiny waist I just wish it were about 1/2 a centimeter thicker. Its weird, It's not that she's "too thin" she just kind of looks like shes missing a chunk of herself. (It may just be the angle)
Also what is that thing behind her? A cape?
P.S. On a technical note, if she has masochistic tendencies she ain't that Mary Sue :-p . That sort of thing leads to downfalls in pervy villains and tragic heroes. So shes cooler for it.