Those are all really great! I agree with the others, the second one is your best.
For the first one, even though I understand the point of the pose, the leg is extremely awkward crossed like that.
The second one I have nothing to really critique. The sitting pose has her a little offset which makes the back seem a bit too straight, but it's not detracting from the image imo.
The third, I can't get over that lump in her right leg and like Geki said, her neck is a little long for her height.
The fourth, the fingers at the tip of her weapon curve in an odd way. She's not really pushing them against anything in that direction so it makes more sense for them to be straight. Even with the curve, her thumb bends at a very sharp angle.
Overall though, very nice. You've got serious talent.
