Although she is not perfectly proportioned, the overall effect is relatively good. A defining background would determine her position relative to the ground. Even a background with a color and a good shadow to anchor her would have sufficed. You are a very good artist and before you submit a piece you have your own inner voice telling you what to work on. If you need some additional form of critique there is always the sandbox.
merged: 04-08-2013 ~ 03:31pm
I wanted to add that the use of color is very good and the costume she is wearing is well
designed. She has a very cute face too. It would be nice if your description what type of medium you used.