I love the expression. The lighting adds to it and supports her look. However, the crop that leaves the right side with the bright area seems distracting to me.
This is an awesome portrait, but to my eye, I'd want to play around with the B&W conversion parameters. In particular, there seems to be a bit of blotchiness, which often happens with a predominance of either the green or blue channels. Hopefully you shot this RAW and have the original. It'd be interesting to see what you can do, if you're so inclined.
Steve, thank you for your observations. I am afraid that I have a way to go before I learn how to manipulate individual color channels. I read that Vincent Versace's book, From Oz To Kansas is about to be released. This will be on my reading list.