One of the things I noticed was that the light source was indeterminate due to the areas shaded. It appears to be coming from the left, in which case the skirt needs to be shaded more on the right in order to achieve an effective technique. Also, the shadows that are on her top blend in a little too much with the top, making it appear as though the top was just one colour. I would suggest making the shading a darker colour so that this doesn't happen.
Onto the good bits; the lineart is really nice! I love the lineart! I love the technique you have used to shade the skin, as it looks realistic, and adds a nice touch to the piece. The hair is nice, but may need a more determinate light source of the halo-shine.
Other than what I have stated above, this is a nice piece, and I look forward to seeing the completed version!