I have two villages in which all the puzzles are completed and heathens are converted. So, my new goal was to keep Granting Youth (GY-ing) to my favorite villagers (JOATs, Retired Chief, runners).

In one village, I GYed a runner nursing mom when she was in her 60s. She's still carrying the baby. I fear that she'll die before I can GY her again. I'm not going to GY her while she's carrying the baby. It's just pointless to keep a runner if she can't do things like fetch the firewood, etc.

In another village, I had no runners at all (bad luck, I guess). But, I had some master devotees and other highly skilled females (no JOATs because I was lazy). Since that village had a lot of untrained adults that never gained skill as children, I was trying to keep the highly skilled villagers in the hopes that I would someday make them JOATs. They were mostly females. I specifically intended not to leave anyone's preference on parenting because I wanted the untrained to die off and I wanted to get my population to a manageable size. I was GY-ing the highly skilled females. Well, they all eventually were nursing moms (even though no one should have been making babies). They became stuck in nursing mom mode as described above. Last I checked, they were all in their late 60s with babies that never leave them. I'm sure they're dead by now. I'm about to go check.

That's been my experience. What I'm gathering from this topic discussion is that if you want to keep villagers around forever, only GY the male villagers. This kind of sucks because my newest village has four running females and no running males.