I agree with the above lol.
I give it 9/10. Make the neck A LIITTTLLEEE bigger. Try shading the shirt more. It seems like the lighting is coming from /your/ left (her right, whatever) so try shading the face from her left.
(Does this make sense? Cx) And the shoulders look kind of messed up separate from the shirt. Like, they aren't gaps, but they just seem off. But it is very nice for your first time using Paint.net actually. Just color the hands. (I know in you post you said it wasn't colored.