Hmmm.
It looks to me like you haven't completely got layers down yet.
It's a good picture, but the line-art looks just a little sloppy, and it disappears under the colour here and there. Remember to keep the colours on a layer beneath the line-art, and to always clean up after base-colouring or shading.
The eyes and the background are especially nice, but I can barely see the line-art on the hair, and that one tiny white line is wobbly and doesn't fit to the light source you have. I'd lose it completely.
Any particular reason she has "mouse ears"? [flap ears...going downwards for one, no cartelidge bridge to speak of except at the top secondly, and no hole for hearing thirdly?]