Hello! :) well, your skeleton sketches are pretty good, you are able to catch the model pose very well and that's a solid step to a good sketch. Now, for the rest of the body "what goes wrong" is that you need to work on your anatomy and observation skills. You're drawing the outline like you're tying up the dots and not like you would actually drawing a human body. For anatomy it's usefull to separate the body in different shapes. So you can analyze each part of the body carefully. Keep an eye on proportions, your skeleton sketches will help you with this. Also, maybe for now, you can make them faceless and focus on bodies only.
Hope it helped!
