I think her left arm should be under the shadow cast from the body, as the light is behind her. I think the same crit goes for the whole piece, it kinda feels like you haven't made up your mind about where the lightning is coming from. Is there a lightsource in front of her, too, that we just cant see? Or is that glowing.. thing (Think it's supposed to be the sun but I'm not sure) actually in front of her? Other than that, I think it is a pretty nice image.
Btw, you should also think about how light effects the colors of different things, not just make all the colors brighter where the is light and darker where there is shadow, it will look more realistic if you have different tones of colors. And the wing membranes should look more yellow-orangeish if the sun is shining through.. keep practicing dude!
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