She is Alena. She's been a Met-Art model many times. Here are a couple of pages for you:
She also goes by Alya on Hegre Art as well, as in these pics:
http://www.xxxslacker.com/pics/38/
http://www.theteenblog.com/Alya-Allstar.php
And she has a thread here as well.
http://peachyforum.com/forums/t/99551.aspx?PageIndex=1