I think the whole 14 thing could still be accurate, though, from what I can remember about some girls back when I was in middle school. Sure, it may not be the norm to have a body like that at that age, but it's far from impossible.
Supahrobo said: A few fans theorize that the human's grasp of time was fucked up while they were kept underground. I go along with this, since... Yeah.
It's not just theory, but the facts are different. Official word is that, on the planet most of TTGL takes place in, years are longer due to the planet being farther from their sun than Earth is from its sun. Thus, 14 TTGL years = 16 Earth years.