Welcome to Gaia! ::

Seems like a pretty solid drawing. Her upper torso is maybe just slightly too thick in my opinion... I might just not be seeing the depth since it isn't shaded...
Maybe it's her breasts. I'm no expert on the subject, and you seem to be a better artist than I am, but I think I'd have the breasts on more of an angle to match the angle of the shoulders. The arm in the back is raised, so I'd think the farther breast should be kinda "pulled up" more. Maybe that line at the top of her stomach/bottom could also be a bit more in that angle/"pulled up". I'd ask for second opinions or do research or something rather than taking my word for it, though.