>>20290292True, some will argue that girls back then reached puberty later, but that claim is false.
Children aren’t starting puberty younger, medieval skeletons reveal
Children are entering puberty younger than before, according to recent studies, raising concerns that childhood obesity and hormone-contaminated water supplies may be to blame. However, our archaeological research suggests that there’s nothing to worry about. Children in medieval England entered puberty between ten and 12 years of age – the same as today.
https://research.reading.ac.uk/research-blog/children-arent-starting-puberty-younger-medieval-skeletons-reveal/ 
