This is a good point. Actually the concept of 'children' being a seperate categoy of people did not come about until about 18th or 19th century.
Leo9 reminds me that in Shakespears 'Romeo and Juliet' Romeo was 15 and Juliet 13 and that was not considered anything speciel by his audience. Romeo and Juliet were old enough to marry, and Romeo to carry a sword and use it.
In the 12th century daughters of the nobility were often married off at 13-14 years old.
A close relative of mine had her debut at 12, I was a late bloomer at 18 though I made up for lost time ;-)
Laws recognize children as 'children' until a certain age, but biology has its own laws regardless. I must agree with the people who thinks that information and acces to condomes are a must.