In all your drawings I really like how you do hair. You do a really good job of layering and emphasizing strands. I think you did a nice job of shading the cheek facing the viewer and also the neck and chin, particularly near the hair.

The face is a little off, the mouth is a bit too far back. Try to think of the face as relatively flat with the features coming off from it.

Some of the color, especially on the arm, seems to either bleed past the line work, or not quite make it to the line completely. If you can get good at using masking in photoshop you can fix that. It might also help you to be a bit more bold with color contrast because it'll give you the freedom to go nuts without messing up the form.

Don't be afraid to go darker with your shadows. Having a strong contrast between shadows and highlights makes the image pop a lot more and generally looks more interesting. The important thing is to get good at blending so that the contrast isn't too jarring, unless jarring happens to be what you're going for, like for something dramatic or what have you.

Overall you're doing a great job of improving, and I really like this drawing. I've also got several tutorials I can PM you that should illustrate exactly what I'm talking about with all the criticisms I've given.

I love that you take a more realistic approach with your art, it's refreshing to see. I'm curious to see what you do next.