In Which Age?

Question

in which age girls start to have a periods and what they have in their period (I mean what they exit from their body) and in which age they stop to have a period
and want to see a guy nude and naked and

want to have.....

these are three questions plz define it seprately

Answer 1

Some from as early as 9 years old .
they excrete blood and other body chemicals to hard to explain here.
naked probably 14 as a guide but some have sex earlier but generally not naked.

Answer 2

I started to have a periods when I'm 12 years old. I think usually girl will stop to have a period when she's 40-ish. I never want to see a guy nude and naked until now. I'm fifteen...