KWED
Scratching head, scratching knee
There is little data from the ancient world, but it's estimated that the onset of puberty was probably around 14-16 years, but as today it would depend on things like diet, health, environment. The better these factors, the younger the onset of puberty.I think you are assuming menstral ages don't change/evolve. What was the menstral ages 2000-3000 years ago?
For example "the average age at menarche in 1840 was 16.5 years, now it is 13 years."
The age of menarche - PubMed