Hi,i'm a digital artist, so i'm not familiar with traditional medium, but the basic are the same so the first impact : this look very realistic, the technique of using charcoal is great. the anatomy seem correct. there are more detail at the face and the hair, focus viewer to this area, and less detail at the border, good simple composition. But i don't know what is she doing, what is the story here? if this is just a potrait then it's fine. She look a bit not happy, maybe thinking some thing?
In the overall: it a good looking piece, show off your techique of using charcoal.