So here's some other shots of the purple dress... I realize they need to be edited (cloning the background (rails, leaves), etc), but I was hoping for your comments on the idea/composition.
I like the comp in #3. The first two just aren't doing anything for me. I feel like the silhouettes are too busy to bring focus to the subject. I think the pose in #3 is much more flattering than the pose in #4.
For those silhouettes it looks like you got the lighting and exposure correct, but now the model should be turned to profile, and I'm not sure about having lights in the frame. After you get a good profile, crop way down close to just show the upper torso.