Good job rendering this portrait. I no longer have the patients of rendering images in graphite like I used to after I discovered my love for gel pens. You got the proportions right. But I do agree with @jocqua on the lighting of the image. There are some inconsistent parts with the light source and the lack of difference in hair tone next to a portion of the face with bright lighting shows that.

I think some minor adjustments might do the trick. This is good stuff so keep up the good work :D