I love the idea and execution! Great use of depth of field and composition to isolate her expression, great lighting. Soft and flattering yet still contrasty and expressionistic.
It's unclear however, what emotion you are trying to convey. Her wide-eyed expression simply looks surprised or shocked. In an interesting way, her expression, is very much like my expression when I saw the photo. Some photos suggest a story, some stand alone by themselves as striking imagery and this one is more towards the latter. I don't know what that all says but if you were going for that, it works great!
I also think that the lighting, expression are all expressionist, stark and work beautifully but her wardrobe is a very casual, floral pattern. I feel that a different choice would have been better. I'm not sure what. Maybe nothing?