This is a quick photoshop demo I did for Mary. She was having trouble making the skin of her subject look like caucasian skin. I made some alterations digitally to show her what she could do to fix this.
1. The original photo you sent me (I bumped up the contrast a little).
2. In the second I mostly just decreased the saturation of all the skin tones and took down the over-all value a step or so. I don't think the skin needs to be pinker as much as it needs to be less saturated. She has pale skin so when she is in shadow it will probably still be pale unless there is a really warm light coming from colorful tree leaves or something. I thought a little extra warmth would make the skin look more vibrant but we went too far:) Looks like she has a crispy tan in the first one. Taking the value down a notch I think will help increase the sense that she is in the shadows. The shadows on the trees are really dark so it makes sense that she would be in a dark place too. Our eyes are going to take cues from her environment to tell us what color her skin would be under normal lighting conditions.
3. Third I bumped up the highlights a little, imagining a softer reflected light hitting her or light from the blue sky coming through a break in the trees or something (instead of a flash). The reason for this is that we can keep some of the general highlight/shadow relationships we see in the photograph (created by the flash) so we don't have to change the lighting scenario as drastically. I also tried to generally simplify/clarify the highlight and shadow skin tones. This is a blending thing which, as you know, if hard to do with acrylic, but especially with skin it is important to get the wet-in-wet blend. Choppy texture tends to read as skin wrinkles or blemishes.
Also note the general shadow under the nose. The wrong shape maybe but as it is in the first picture you just have a dark line describing the contour shape of the bottom of the nose but not giving it a over-all shadow underneath.
Finally I added a little accent highlight at the top-left side (our top-left) of her hair, face and shoulder and a few little glowing hairs on the back of her head. The reason for this is that it gives us another cue for what her skin looks like when lit by a a direct light, so we see clearly that it is caucasian skin. It also (perhaps) ties the figure in a little more to the light in the environment - we can imagine that the light highlighting the tree is cutting through to hit her a little bit. You could then go back to the trees and see if you can make this common light source even more apparent. The highlight might be too dramatic, but you get the idea - trying to give some indication of the figure occupying the same space - getting hit by the same light as the trees, leaves etc.
4. I just added a little warmth to the over-all picture to see what it would look like. Not much of a difference but something you could accomplish with a glaze.