I think the hair shape and lips are just right(I always prefer less overall details to more). The colors are appropriately muted/gray making everything look really well balanced. I really like this, excellent portrait!
Setting aside my attraction to elf-ears, the way I look at this picture is by making eye contact, followed by a look at her lips. Both work remarkably well and instantly transform this from a "pretty girl" to "who is she" and "why's she smiling at me? Is she smiling at me? She seems slightly amused and confident, why?" There's a person there. The expression and look evokes a response in me.
The almost invisible second eye and second light source bringing out the shape of her face give this additional depth.
She's beautiful, and her lips in particular are very sensual.
The only issue might be with the hair towards the top-right. It's probably good that there's little detail there to distract, but on the other hand I'm left scratching my head just what kind of hairstyle she's sporting, how's her hair put up like that?
Thx for the reply and critique.. There are quite a few mistakes in this piece actually, the lips are too plump.. I can say ugly plump, and the lighting could've been more defined, but it's an old one after all, and it was made for 150*150px avatar)) so moving forward ^^
did you have someone special in mind when drawing her? somehow she makes me remember T'Pol from the latest enterprise tv-show. her ears are larger and the hair longer and wilder, what shall I say except: fascinating!