Well I have found that mixing the G4 body, V4´s FBM´s and breastmorphs with Lyrra´s "V4 shape of a woman" (DAZ) gives some decent preteens, I´ll put up a render or two when I´m done with my "American Outlaw" series.

But I think I made some progress allready with V4, in this render:
www.renderosity.com/mod/gallery/index.php?image_id=1777990&user_id=530312&np&np
She´s supposed to be about 11-12 years old.