>>6608
I think the biggest problem is that proportions get fudged up as you move down along her body. The hip is where it is most noticeable... her left hip is much more inflated than her right, even if you're trying to go for the angle.
About showing depth, showing us your construction lines would be good, if possible. If you don't know what I'm talking about, the attached picture illustrates construction lines. Use them.
Other notes...
Aside from the construction lines, I think the problem with the skirt is that the hem of the skirt is perfectly horizontal, while the rest of the body has a slight slant downward (eyes, arms, leg, etc). Also, you might want to put some shadows on the far side of her left knee to show depth. Eyes are pretty well drawn, the angle might be a little steep though. It would really help if you added a nose.
Oh, and the canvas/easel is totally off...its perfectly horizontal and 2-D! Little things like that can really mess up the overall perspective of a picture. Otherwise, pretty good job, keep at it and post some more when you can!