Success!
I guess the week and a half of higher humidity finally got her going, as it looks like she worked on shedding while I was at work today (she'd made no real progress in over a week until today). Long strips were hanging off her and littered around the cage. About 30 mins of letting her crawl through a wet washcloth got the last 6" off. Yay!
Thank you everyone for the tips. The video was a great visual, too, as I'd read about soaking, but it was useful to see an expert do it step by step, and to see how the skin can be rubbed off. I'm really feeling my nubie status!
My goal now is to keep that humidity up so I don't have to do this again!