Its cute.
Good use of shadows and lighting.
The image still looks a bit flat.
If you had a light source coming from the far left,
Maybe make the colors on her back right arm darker to show the shadow being cast from her back.
Then have her left hand and maybe the left side of her face brighter.
Really it depends on where the lighting is coming from.
So maybe make the shadows slightly darker and the highlights slightly brighter.
It'll give it more of a sense of depth.