They are pretty good. As for feedback:
Render 1: The skin and eyes looks very dry. I would look in increasing the glossiness/specular a bit to give both the skin and eyes a bit of shine. I would say the lines in the neck are a bit to harsh as well considering the young look of the face. The lightning might be a tad to much it feels she is shinned on with a flaslight from several sides.
The second render is a bit wierd. Is she half a zombie or something? Her feet, legs and but got a wierd red/greenish rash on them which gives it a very sick look. I don't know if thats what you are going for, if it is it looks fine. The upper body looks fine. Lightning is a bit boring. seems you got a spot light at both the left and right side of her (according to the shadow on the ground). It works if its a photoshoot but doesn't make much sense for anything ells.