I think the neck and chin are too connected, Overall great, but background might be better with more depth

It's moody and cool that you gone to complex shading - that brings a volume and made figure more 3d.

But I highly suggest you to work a bit more on the neck and head areas - something just doesn't look right: looks like neck just goes into face without a chin (maybe shade it differently?), nose seems to be too wide, and it's hard to tell what's happening with her right arm. Study bone and muscle structure of neck and shoulders. Note how clavicle affects the outer shape and how it changes position in different poses and what happens on the transition from chest to arm when arm is held up (and don't forget about gravity!). Definitely google some refs - this stuff is complicated enough to draw it all out of head.