I guess it says something when this is the first time I have reviewed art.
Great job, I love the fine detail of your girl. I, like others, am having issues with the background. I, from a naive talentless biologist point of view, feel that it's too absolute compared to her fine lines. My eyes are drawn to the background and not her, I have to actually work hard to focus on her at all. Instead she has sunken into the image.
My thoughts are that possible a brush stroke on the background might make it look more similar in media and therefore one congruous piece, or a drop shadow to pop her out of the image.
Really, the fact that I am saying anything means that your work really struck me, and great job.