Wimmens are at their peak around age 16.
But that's a no-no age.
I think, historical record estimates Mary was 15 -16 when she was mother to Jesus .
Maybe that young only applies to "immaculate conceptions" LOL

Until modern medicine, there was a much greater risk of maternal death during childbirth.
In the modern world, women want to bear children in their mid 30's and early 40's now for financial /lifestyle reasons.
Sounds reasonable, but mother nature is a real bi-atch.
The best biological age is around 18-29 for most females . Biological vs economic needs don't always line up.