[dragonwriter]

> For instance, consider the depictions of Mary throughout the centuries. In most, Mary is depicted to look like a young woman, but not as a 13 year old kid.

In quite a large number, Mary looks like a woman of young-but-marriageable age of either the same culture/ethnicity of the place where the depiction was made or one idealized there.

> Still, even the young actresses act mature

Which, given the depiction of Mary in the Bible, is unsurprising; even if social context didn't play a role (along with brain development) in maturation, it would be inconsistent with the source material to depict Mary as typical of her age.