...and made a few observations that I hadn't made pre-scan.
1. Go darker!
Amp up the contrast, but don't lose mid-tones in the process.
In doing so, I might;
2. Make her look more soft and rounded where she ought to be. Also;
3. Pay more attention to the direction of my shading marks,
4. Work more "softly" and delineate shapes of shades instead of cross-hatches.
Oh. And 5. Shave a bit off of her left, top lip (on the right.) But that's minor compared to the technique stuff.