[Karin Wells]

I see this painting as an opportunity to lose and find some edges. Also, I think that the light is even more subdued as the face and lower arm turn away from the source.

Shadows are a great design element and can be useful to integrate the background and foreground for a more unified painting. It is OK to "play around" with the lighting a little in order to make more interesting shapes/patterns of light and shadow.

The background is usually not a place where you need a sharp focus or "harsh line." Oftentimes, a "mere indication" is enough here.

I've taken some "radical liberties" with your painting to illustrate what I'm trying to say. I hope that it does not offend you that I did this, but pictures are so much easier than words here...