True Buck -- but a "believer" will look at that kind of scientific possibility and call it proof of their belief; and skeptic will look at the SAME possibility and say it means there is no proof one way or the other.

13 year olds are, as pointed out, remarkably bad vessels for giving birth. Any ideas about the age of onset of puberty aren't very accurate, since we really don't know what was normal back then.

However, just because the plumbing is in doesn't mean the house is ready to be occupied. But we also get into theological ideas about the relative purity of children vs. adults; the idea that children are more pure and innocent (which we still ascribe to today) is a very old one. So someone on the cusp of childhood/adulthood, would be more theologically "pure," and therefore an appropriate *spiritual* vessel. An omnipotent God, of course, could get around the physical issues of a 13 year old mother.

Some of this reminds me of arguing long ago with other kids about the existence of Santa Claus.
"How could Santa deliver todays to everyone in one night?"
"Because he's Santa and he can stop time."
"How can he get down a chimney if he's so fat?"
"Because he's Santa, and Santa can do that."
"How does he know who to bring toys to?"
"Because he's Santa, and Santa has special powers!"
"Then how could ELVES make all those toys in just one year?"
"Because elves work for Santa, and he gives them special powers."

:D