Huh, very nice. There's a very noticeable improvement from the girl on the last page to this. Is Visi tutoring you in real time or something?
Still, I feel (with both) there's a bit of an issue with the source of light, namely that it's not clear where it is. It mainly seems it's coming from above, but the most prominent shadow is on top of the head and to the right, and there's no clear indication that there's two sources of light. In general I think the problem is too much symmetry in the shading. There's a bit of shadow both above and below, left and right, on her body. Unless the source of light is from directly above (which can give a special effect in it's own right), shading is all about asymmetry. You can add a bit of shadow on both edges of an object
, but there should generally be more on one end than the other. Shadow can also be used to get a sense of distance, in addition to shape, so I would also tend to shade things like hair behind the person a darker shade than the rest.
Also, I wasn't staring at her boobs
(her eyes are more interesting).