In case anybody cares:

I also reset a much younger worker to Healing--she'd become Adept at it in her *spare time,* after I showed everybody about Studying medicine as an alternative to doing Laundry, etc.--but my old Doctor survived the several years overnight. My two oldest died during that time, but it was old age, not lack of Healing.

(Tangent: In a VV2 log, I had one senior guy who regained health to 96%, and then died of old age in the very next line. Clearly, you can be in excellent health and still go when your time comes.)

I did end up having to train a bored 15yo in the morning. But if I hadn't mistakenly grabbed him previously when he was about to Listen to my Chief's once-a-day Lecture to him--and the other kids--it wouldn't have been a problem. He'd have had a little skill to get started with, like the other kid who finished growing up overnight.

(Tangent; includes vague Spoiler: I don't know WHY I don't trust the game mechanics more. If I'd just held back after I let the chief tap the boy . . . Same with needing a water source for one of the Puzzles; if I'd just sent a worker to each of the two obvious possibilities, and assumed equipment would appear as required, I wouldn't have had to read the Guide!)