She has a dark V shape behind her right eye, her headband isn’t connected to her head, and she has light shining up her nostril. It’s probably just because you have some wierd lighting going on there. Other than that, is pretty sweet.
Wow what a fantastic start, the clothes realy suit her, looking forward to updates.
I agree with Rozzy that you’re getting too much light in places it probably shouldn’t be, the nostrils and also in the area where the lips meet. Hard-edged shadows are not complimentary to the face. Maybe using RT Area light(s) would help both? A bit too much transluceny to the skin, imo, though that could change greatly with further shader development.
Yeah, I shrunk down the skin scale a bit and have completely abandoned buffer shadows, which offer lower quality shadows, but had the nice bonus of ‘not taking forever’. 
Anyway, stage two. I know the lower eye-lashes are a little off, I’ll get rid of some of the rogues for the final product, and she still needs eyebrows, but I’ll get them when the rest of her face looks alright.
The light’s still not top optimal but she’ll be in an actual scene at the end, if everything goes to plan. 
The model is looking very good. The eyes reflecting the light is very well done. I feel the jawbone is a little awkward and not well defined enough while the chin is too pointy. This may have to do with the ears being a little too high. There is something strangle with the shadow. Some unnatural very dark spots and some abrupt gradients. There is a sort of halo that looks like a sort of geometry doubling that adds a fuzziness to the image too.
Tilting the head just a little bit and turning the eyes away from spot center would add that little sparkle of life.
Overall, it is looking very good.
The skin is looking very good now, well on the way to flawless imo, except that the texture on the lower lip looks a little inverted, kind of like ridges rather than “cushiony” bumps. May just be the lighting, though. Same for that powder-blue “arrowhead” shape on the right cheekbone.
Hi Zombiejohn,
Great progress so far. Well done.
If I may give some advice: Don’t spend too much time trying to refine the SSS factors whilst in a default/generic light setup. The amount of SSS to use is most times very dependent upon the specific light stage of a scene. Put her into your scene, set up your lights and then tweek the SSS parameters for the most realistic results!
I would hate to see you have to reset everything!
Oh and don’t forget that compositing ramp shaders over the top can help acheive cheap rim lights for that fine tweeking!
Cheers,
Josh