I'll agree with Adam, on the peach fuzz, and the teeth. Teeth could be a little less "bumpy"? I understand, Iray uses Normal maps instead of bump maps, but if you could lower the normal map influence on the teeth... in pictures, teeth appear sleek, and smooth. For the peach fuzz now, it would do great if it was more subtle, for a female character anyway. Other than that, my advice would be to pose her for "eye on the camera" rendering... in close-ups, it's always important to have the model looking at the camera (and, the image viewer later on).