Eyes closed makes her look vulnerable, and the soft light and the softness overall work with that. I think this is a good idea. I like the sense of vulnerability and sweetness combined with the slightly firm set of her mouth, corners turned slightly down. One gets a sense of something going on here, a sense that she's making herself vulnerable, and yet holding herself back a bit, or a little reluctant. Perhaps she is considering how wise this choice was.
These are fine themes to explore. You could try a little higher key look, more light, more softness, and see if she can push that ambiguous vulnerable/reluctant expression a bit more. If you want to go a little more radical and edgy, add in a tear, or some smeared makeup. Ok, my preferences are showing a bit much here, so I will stop
The other poster's are correct in that you are not following standard rules for portraits, but obviously you're not trying to MAKE a standard portrait, so whatever.