Holy...the line art in this is nothing short of amazing!
I'd be interested to know what your secret is to get lines that aren't bumpy when using the brush.
Proportions are good as well as the shading, I especially like how you managed to make the clothe crumples unique from other ones on the shirts.
The only thing I can point out that could be improved is near the top of the her head on the left there is a small line that overlaps a couple of other lines on the head.
All things considered it is an incredibly minor critique as there really isn't anything else that I could suggest to improve upon. :P
Excellent work as always!