You have a nice piece here! I love your cross hatching shading work! Cross hatching can be so tricking sometimes and turn out horrible if you don't do it just right, but you seem to have gotten a nice flow going for you here in this piece!
As I look at this piece, I see you have a nice handle on proportions and movement! That's half the battle!
Looking at this piece with a critical eye, the biggest thing that stands out that needs some slight improvements would be her top hat and her arms from the elbow to the wrists.
First the top hat; it needs just a slight size adjustment bigger so that it would theoretically fit her head. The size it is now she would barely be able to get it on because the hat's opening is smaller than the size of her head. (it's a mistake I use to make as well )
And her arms, they're great, but her right (viewer's left) forearm is longer than than her other one. That top hat might have confused your eye a bit on the length of the arms, but if you were to put your own arms in that position (check it out in a mirror) you'll notice that her left arm (viewer's right) should be reaching higher than the bent arm because it's straight and doesn't lose its height by being bent.
Aside from that, really nice piece! Hope this helps you out in some way