I don't know much about portraits, so take all of my critiques as personal preference and nothing more than that. The reflection in her eyes (the ring of light) is distracting to me, and her shoulders seem awkward to me. I really like the lighting, and the background, and the intense look on her face.
I like this portrait, it grabbed my attention immediately. One constructive comment, and it's just my opinion, but may a little more contrast within the tonal range across her face. There is great depth to her hair and eyes and a little more shadow in her face would support that depth even better.
Those circular lights always seem a little fake to me, in the eyes... :-/ Otherwise this is of course a very stunning photo. Contrast is lovely and composition is as well. The model's expression is a bit sterile but I think that really works here.
The catchlights seem a bit overpowering to me...especially given the soft focus on her hair and portions of her skin. Just my opinion about an otherwise fine image.
Ah, a ring light... I love what it does to the features of the face (she's very beautiful here). I don't think I'll ever get used to the eyes though...