Yeah, you don't see any kids eaten in the TV show, just already zombified Sophia getting shot in the head.
The comics however... whoo.... two kids decapitated by a crazy prison inmate, a woman holding hands with her son and Carl when her son gets munched on, then her arm chopped off by Rick to save carl.... rape and torture scenes. Definitely adults only game material. But a kid getting eaten or shot? Not a big problem ESRB-wise as far as I see it.
MW3 a girl gets blown up, Bioshock you could harvest little sisters, killing them. And any online game you play these days is inundated with little 8-12yr old bastards using their high pitched voices to scream in your ear, and I've killed PLENTY of them in game ;op
Face it, Duck needs to die! lol jk I don't really mind him, but I am gonna play through multiple times to see everything.
Oh and Skyrim/Fallout there's mods to make noone invincible. Skyrim kids are all evil