I love the overall pose, crop colours, expression and mood which make it a great picture.
Areas that I would change :
a) less light on her torso - I find it distracts too much from her face which I think is far more interesting. I think the light should be just an accent. b) her right hand seems slightly strange just appearing there - I think I would remove it alltogether.
But these are tiny minor points to what I think is a great image and will be trying to emulate in my work.