I remember reading once about an indian tribe who used to take their adolescent boys out into the woods for a ceremony when they were around 14 years old. Expectations of manhood were explained to them in a ceremonial fashion and the event culminated with leaving them for several weeks all alone to fend for themselves. When they came back, all of their toys and articles of their childhood had been taken away. They were expected to be Men from that point on. Girls have their "transition" built in biologically. Boys really don't, unless the society marks one.
Beg to differ.
A woman/girl is more than just her body.
Some cultures do have a "coming of age" ceremony for females. The Latin cultures have their quincenara. Our American culture once had the "Sweet Sixteen" party for middle-class girls or the more formal presentation to society for debutantes. I think such a ceremony about the mantle of adulthood and all its responsibilities should be retained and encouraged for young women. Female maturity is not just "Oh, your body is capable of making babies now, now this means you're a grown-up woman. " No. It's so much more than that.