what site did you get the pic from ? that might help mate
The pic he attached has a Tumblr name on it, so he probably got it from there, or from someone else who got it from there. Tumblr blogs are famous for people posting one photo of a model without saying (or maybe knowing) who she is or who took the photo. So, we're back to facial recognition. I think she looks vaguely familiar, so if enough people see this someone might ID her.Too bad theres no site tag.
EDIT: I just tried TinEye and got 0 results.