In my current game, I have a female villager who can't seem to get pregnant again despite having four children already.

She is 53, I have two population huts, the population is 31 at this time and I am not getting any 'need more huts' messages. Yet she has gone indoors dozens upon dozens of times. I tried setting the rest of the males to parenting, but it doesn't seem to help.

I suspect she has simply gone past the point of childbearing, but I've heard of people getting mothers who are alot older than that.

50 is the limit when YOU try to get them pregnant and when they try on their own while the game is open.

However, there's no limit for them getting pregnant when the game is closed. Put her on "Parenting" as her preferred skill and close the game. When you come back (after some time has passed, obviously) she will probably be nursing. I've had mothers in their 70's that way.

Oh, didn't know that.

That would explain the guys not being interested when I had them on parenting.