Actually, it's not artifical, this doesn't happen all the time, but there are cases where the body does mature faster then normal. Seeing how everything in starts to get in motion at the age of 10. It isn't that surprising (until people found out her age, ouch). When I was 13, I knew a few girls my age that had fairly large chests. It's a matter of genetics. You gotta admit though, thats a hell of a pair.