Beth: We are all here, cheering you on.
I have to agree with Steven. One thing Bill Whitaker did while I was with him was to spend 6 hours painting a headscarf and hair on his subject. He then spent about 6 hours another day repainting the whole thing because he felt he could improve it!
Everyone has their own take on things like this, and eventually you have to say "It's Done and that is good", but don't sell yourself short if you still can take time to improve it. My opinion only. I think you are doing a wonderful job.
One more bit of advice: I see long strokes down the length of the arms. Lay your paint down with the length of the form (arm, cheek, forehead, finger, etc.), but then stroke across the form as it will make it look rounder and blend your strokes better.