my advice is to work on the eyebrows some.  they're usually the best indicator of a newbie texture.  see they way they don't really hold a shape, end early, and fall off into the eye area?   i think they would look better if they ended more distinctly above the eye, and were more "shaped".  i put that in quotation marks because i mean the natural shape people's eyebrows have, not the plucked look.

i have to agree on the lips.  those lips look at least a size larger than mine or anyone i know, and i'm black.  i also don't think i've ever seen a woman with an upper lip larger than or as large as their lower.   so even though i know you'll probably ignore this (understandably - your character, your taste), i'd suggest toning the lips down a tad and making the upper lip smaller.

i also have to suggest changing the eye shape a bit.  everyone was commenting on the head, and i kept thinking, "it looks like default v3."  but then i looked again, and thought about it without the eyes (and nose, actually), and i thought ah! that's what's giving that default/manikin feel.  if you use some of those references you have, and adjust the eyes and nose based on those, i think you could increase the realism of the character 10 fold.

the only other aspect i'd mention is details, and it looks like you'll be adding those.  i'd definitely vote for some of the veins people were mentioning.  i love the pale look, but if you want her to look real instead of airbrushed (a big if, airbrushed is popular), her skin shouldn't be uniform.  most people's faces, some areas are a bit redder, some a bit darker, some a bit paler.  and if you're going for a more real look, you'll beat out almost everyone in the market if that includes real rather than painted makeup.  i just about always use the "natural" version of textures because of how unreal and jarring the included eyemake up looks on a really detailed texture.

as everyone has said, she's already pretty, but with more detail she can be distinctive and more than just another pretty face.