Seems no one has said anything yet. But do not fear, Val is here to give a helping hand.
I can see that you have the basics down for "skeletons" of characters. I do notice you use the joint balls in
an odd manner. Normally, one would use the outller line of the joint balls as part of the skin, you literally draw next
to it, making the arms rather "thick". Try following the "doll" instead of giving it a second layer.
The same goes for the wrists.
When laying down, breasts naturally take a slightly different shape than standing. It would look better if the breasts
of the right girl were adjusted a bit. First is fine because of her position.
Main part is, the legs. You need quite a bit of experience to create coming front and dissapearing well. What you need
to do is; knee bigger, less side bended, then just add the rest of the leg. It is pretty difficult to explain. I hope it
works. I can always try giving you an example of how it should look like. You can try taking reference of some pictures
(Ecchi ones usually work really well for these things imo).
Aside from that, right hip of girl on the right is not symmetrical to her left.. her neck looks odd the way her head is
on her body somehow. Other girl is fine aside from the legs.