The law prevents children from getting jobs or renting apartments in almost all situations.
The gap between physical maturity and psychological, economic, or social maturity is a serious problem. It would be instructive to observe how other societies have dealt with this in the past. I’m thinking of classical Greece, for example, where boys/men practiced homosexuality until they reached their 20s or older. Then they married young teenage girls. Homosexuality and prostitution seem to be common, historically, in societies where men delay marriage. Fornication of young women wasn’t as common.
It seems to me that a lot of misery is in store for the most vulnerable members of society, especially the babies.
I really doubt that was common, nor do I think the child would have much choice in the matter.