I did a sketch and cleanup of a larger view of Natsumi. Hopefully she won’t get mad if she sees this (I’m married to her now!).
As in other images I touched up, I’ve put the intermediate stages here, beginning with the raw photo of the sketch, moving through stages of touch-up in gimp.

Make it look like the outline of an 8-bit game character…

A bit more detailed outline work…

After getting a bit of the easy smudge work out of the way…

Now a bit more detail work…

And some brightness/contrast work…

It appears I stopped here. I never did refine the hard pencil outlines. Meh.