Been a long time since I didn't visit this section and a good surprise indeed. No lake on the sunset but some human beauty! Rob C would be happy too.
Shot number 2 is cool. Reminds me a little bit a Cooter picture.
Looking at the overall render, there is something (and not specially a criticism, depending on the author's aim) on the shade: they tend to have a reflection of the pink that create a different dominance. I'm sure that If you look at the shadows in PS you'll find that they don't belong to the same tone from a side to the other. That's visible just like that. Some shades belong to the red family, while others are much more balanced with the overall skintone. Those differences gives a sort of "metal effect" that I don't dislike but maybe a little too shy in the context of an assignement. If this "metallic" effect was on purpose, then I would go even further on it to show clearly that it was intentional and not an unwanted effect. On shot 2 you got thios "metal effect" on the back arm but the premier plan is free of it.
Then, the transitions between shadows and mid-tones are in some cases different, according to where you look at. It's like some parts (the face) have been more retouched but it could also be the lightning. Or it has been rather over-processed or not processed enough. I can't answer to that but I have this sensation. On the first pic, the light on the legs "should be" the same that the light on the arm but it's a completly different treatement. See that the lightning reflection and transitions are not ecuals. Try to avoid that as much as you can, unless you want to strenghten the muscles and shapes, wich is the case here. So it really depends on the goal. Be carefull on details like the elbow bone when they shape (left arm), better erase it because it doesn't add info but makes her harder. (this woman, good looking, is not easy at all anyway from a photographical point of view. One of those person that are more difficult to get it with so your results are indeed encouraging).
Image 3 is the hardest as being the most artistic orientated. There, you need IMO the same: don't be shy. If you choose a path go for it completly. Personaly, there are details I'd like to see on the shoes so it balance the hair, and details I would erase on the body and just put: shoes-hair in the vertical axis as detailled and body lignes just suggested. But that's just me.
To me it's a nice and promissing work, you're almost there.
I don't know what is your training when it comes to post-processing with models, specially the lightning. As I said, you're not far and if you keep going this route you'll end to get it. Very simple, if you don't end with minimum 10 layers, bad sign (I'm kidding). We generally work with channels and "calculations", sweets like that. Avoid like the plague (if it was the case) the magic plug-ins that suppose to fasten the workflow because nobody learn with those shortcuts and I recommend to work with C1 or Phocus to rawdev. I give you here a link to the guy I work with, you can check the skin-tones and lightning is generally very simple. When not strobes, he uses Kinos. Reflectors are crucials. MUA is key. You can be the best shooter or light director, if the MU is not good it would ruin the shots. So if you feel something's wrong, it might not necessary mean you did it wrong. All aspect on the chain are important to get good results with models.
http://www.pepe-botella.com/private-site/private/editorial-priscilia-y-reyes/priscilia-y-reyes.html (almost no post-prod on that, just lightning and smoke, Full frame Canon)
All my best in that route.