While you're definitely on the right track, it looks like the torso and pelvis aren't part of the same pose (does that make sense?). Actually, it doesn't make sense. I don't know if a contortionist or someone more flexible than me could do it, but my back would have to be broken to do that pose (yes, I tried it). That aside, she doesn't appear to be wearing a bra. How are her breasts being held up like that? Apply gravity.
That you know what you're doing is especially apparent in the line quality and pretty much everything besides the boobs and the pose, so I'm a bit hesitant to mention the shorts.
. . . I'll do it anyway. I've neglected my fashion studies, so I might be wrong here, but the way the shorts wrap around her butt makes them look a bit too short to be shorts. Like they wouldn't quite cover her crotch. Again, I don't know what's going on in the front there, so take this paragraph with a grain of salt.