Also I think the number of deaths from childbirth were pretty high back then.
That would probably be a good motivator to have children
later rather than as soon as the girl hit puberty. In fact, I believe this very issue was lampshaded in
Romeo and Juliet. If I remember the verse correctly, Paris tries to convince Juliet's father to let him marry her immediately by saying young mothers are happy mothers, to which the father replies in a way that meant that young mothers like her either die, or are horribly damaged a lot of the time, and that he should wait a while longer.
