The first thing i make notice of is the proportions on the legs. They don't sync up with the torso, and while the first leg could likely be caused by (what appears to be) the leg stepping forward or up, the second leg is completely out of proportion. (It's to long).
Other notable observation would be the breasts looking a little awkward, but i think this may just be a slip up redrawing it.
The arm is actually to long as well, hanging far lower than it should given the size of the torso.
This drawing was from 2007 I think all my drawings then had abnormally long arms and legs in proportion. The image from the novel is also from a low angle, and I still struggle with high and low angles.
She looks very sexy and powerful in that stance. Her proportions are a little off, her arms are too long. The hands should hit at the upper thigh and the top of the arm should be equal in length to the lower arm. Nice work, thanks for sharing.