The rules (epublished... somewhere...) for younger-than-adult PCs were humiliating to the point of unplayability.
There was a Signs and Portents article on playing kids within the SC2.0 rules, it's available on the main Crafty site...
Yeah, that's somewhere all right. Existing, however, doesn't make them good. Although it's not mandatory a PC take the Young or Teen talent from that article, it's the only way to get any advantage
from taking an age other than adult. Being ages 7-11 means a -3 to Str & Con and a -1 on Dex, Int, Wis, & Cha, while ages 12-15 means -1 to every
ability score. That's monstrous.Nothing
those Talents provide compensate for the ability score hit. The only advantage to either is that the Young talent makes your PC Small, which is, I'm pretty sure, otherwise impossible outside of species talents and feats. Seriously, Spycraft 2.0
says you can just say
your character's an (adult-sized) Fierce Playboy toddler (which is weird, but whatever), so you don't even need the Young or Teen talents to take the underaged feats.
Children as PCs, under the rules, are only good for shooting yourself in the foot, which is a shame, because, as I said, there's a whole genre there.