Very nice.
I'm not sure if you did this by choice or if you didn't notice, but your missing the cat ears. I know it doesn't make sense, but I did it cause two sets of ears is not supposed to be possible. The way I see it is that she's a catgirl (by race) dressing up as a bunny, like a confused halloween costume. Also, she usually has red hair, but hey, at least you added hair. I hate how the cabal hat can't combine with any form of hair. The wings look good and wouldn't worry about changing them.
This is the first piece of art that isn't a sketch, thank you very much.
Ack, y'know what, I didn't even notice the cat ears 
They do kinda blend in there, but now you've mentioned it I do see them >.<
np, I can see how you wouldn't look for more ears after seeing the bunny ears, I mean why would she have two sets of ears? Actually the brown hair threw me off more cause I've never seen her with brown hair.
Still good work none the less.
I originally drew it as a kind of orange/red hair, but I think the shadow makes it look brown 
[Link]
I specifically chose this costume because it was difficult, and I decided to experiment with the pose, I think over all it worked quite well... the wings could be better... but the could be worse too, so I'll leave them as is
Hope you like it Gata