Attached Link: http://www.buffyupn.com/player_witch.html

Pretty close. Allyson has fairly prominent cheekbones...I can't quite tell from the angle of your render if that's where the crease is coming from or what. Maybe thin the upper lip a touch more. The brows need to be little higher, and she keeps them very thin. I think her nose is bigger too (i.e. less pinched). There's a fairly good face shot at http://www.buffyupn.com/player_witch.html. The other pic they have is too airbrush perfect so its not a good one for reference (she never looks like that on the show). I'm sure you can find good pics of her on Buffy fan sites to work with.