Okay!
First thing's first: the shape. Forget the shading until you get the shape correct.
The neckline could curve a bit more...it's too stiff feeling to me.
The other biggest problem I see is the hem of the top looks like it's not rounded enough...it's awkwardly sitting up on the hip on our right..needs to come down a pixel or two.
I feel the sleeves should curve in the opposite direction they currently art. Right now the ends are lowered than the middle and I feel it should be the opposite
Here is a pretty good ref for shape: