Hello - nice shooting!
I will try to make my C&C as polite as possible. I will preface it by saying my rule of thumb for C&C - If you intended to do what you did that I'm critiquing, then ignore what I say. If not then take it with a grain of salt. After all, it's just my opinion, and you know what they say opinions are like...
Image No. 1: The lighting here is a little flat for Rembrandt lighting, if that's the effect you are going for you may want to move your key a little more to the left. The composition and crop on this one seems a little off, you might try cropping from the right somewhere into her hair. Also, you might consider a rim light or hair light to provide greater separation and some pop (if you are going for a glamour look as opposed to a flatter fashion look).
Image No. 2: Again I don't care for the crop in this picture so much (cropping out part of the arm to camera right). While I often use tight crops and cut out body parts, it really doesn't work when the rest of the body is presented in full - my rule would be to either crop in tighter or show it all. The way the legs are crossed makes the pose look a little uncomfortable and isn't really flattering. What focal length were you using? To me it looks like you used a wider lens, accentuating her feet (making them appear a bit bigger). For this model you might prefer the greater compression of a longer lens. You seem to have used a bit of a hair light, but I would have liked greater separation.
Image No. 3: This one is my favorite! It looks like a real fun shot! I think you posed the model very well for her body type and you made her look very pretty. I like the use of the rim/hair light, but you have to be careful with hotspots as evidenced on her neck to camera right. You need to balance the lighting better over all. The brightest parts of this image are the back of her neck and her left breast (camera left). Her face is left mostly in shadow. I think this shot needed a repositioning of the key light and better ratios. You might also change up the composition a hair. Also, watch for the wrinkles in her jeans. I also would have liked if she had at least a hint of a smile in this shot.
Image No. 4: This one has a nice high key look. I'm not always a fan of bleed but here it seems to work. For this model I would have shot the profile with her turning SLIGHTLY into the camera to thin her out a bit, and had her really tighten her abs (I do this with all models, and is in no way a reflection on this very pretty girl). The colors seem a little washed out and the image could probably be helped out with a levels or curves adjustment.
Over all I think you might want to explore the rule of thirds a bit and try and incorporate it a bit more into your shots.
So those are my thoughts, thank you for sharing and I look forward to seeing what you post next!