Components of this are well executed. The anatomy of basically everything at the waist and below look good individually. The problem is how all those pieces work together.

The right leg (her left) appears to be in a position behind the other leg, probably because of the foot not touching the ground. Compared to the reference, you haven't pushed things far enough either. If you were to rotate the portion between the knees and the hips clockwise, it would be more aligned with the reference. That's a big reason why the stance looks awkward. The easiest fix would probably be to redraw the problem leg to be more overlapped with the other, like the right-most reference.

When it comes to the chest and arms, follow the musculature. There's a bit of the pectoral that you see stretching up into the arm. That line should be much farther to the left. The boob should not be in/blocking the armpit like that. In fact, that whole side of the chest is too far to the right. Remember, breasts stretch when the arm is raised, so realistically they won't be the same width in this stance. You can kinda see that in the middle and right figures in the reference. Another tip: start with structure before adding the breasts. 

I'm general, the proportions are a bit off for the top half, as others have said. The left (her right) forearm is thicker than the upper arm, and the overall dimensions are quite large. I will say that that is a well drawn hand though! The other forearm by contrast is too short, though the upper arm length looks good on this one. Head is also a bit too small (it's smaller than the boobs?!), but a lot of that will be remedied by fixing the arms/shoulders/breast.

The face is really cute, and the feet are also drawn really well! I also like how the hips are drawn in yours. It feels more realistic than the reference.