There is no "ready to use" M4 PreTeen/Teen that I'm aware of.

This one I made myself in ZBrush.

But with single-axis scaling now fixed in Poser 9/PP 2012, it should be a lot easier to "age-up" the Kids-4 or to "age-down" M4.

Still, to get a really convincing result, you need quite a bit of custom morphing. (Which you then will need to transfer over to the clothing)

 

I've already seen very convincing preTeens/Teens made from Genesis, but, alas...