https://time.com/6301466/covid-19-early-puberty/

There’s no conclusive answer about what causes premature development, though research shows that the constellation of factors at play includes stress and trauma, as well as lifestyle habits like poor diets and lack of exercise that are tied to weight gain in children. In many countries, pandemic measures saddled children with this exact package of pressures. It’s no wonder that precocious puberty rates soared.