Great start! I did an edit to highlight the importance of a more definite light source.
I couldn't help but give her some little eyeballs lol. The left leg feels a bit odd up close, but makes more sense when the viewer backs up. The overall resolution that this piece is displayed at will effect the readability to some degree.
Hope this was helpful!
-Johnny B.
I made a color change as a test right before I saw your post. I will give the light source method a go. At one point I was thinking about giving her a nose. Just a simple dot. The big problem will be animating.
A color that provides more contrast: