I like the tones, but I think I'd like the overall shot a little better if the subject were more in focus. Just my opinion, but I am no expert with portraits.
I like how she fades into the background, yet has enough skin showing to have a nice glow. The one thing that bothers me about this though, is her necklace. In the soft light it looks almost like a weird bump on her skin... smooth would be best, I think. Nice catchlights in the eyes.... really makes her face stand out. (7)