Domestic cats are a lot more social than they get credit for. They're solitary hunters, so they don't form tight, authority-driven, cooperative packs like dogs do, but ferals do form loose-knit colonies, show affection, share extra food, and cooperate to drive off invaders. Female mammals in general are fiercely protective of their young, and the differences between children and adults are common across all mammals--undersized limbs, oversized eyes and head, awkward movements, high-pitched voices--so they easily recognize human children even if the kid is bigger than the cat. I've known a few cats that wouldn't let adults touch them but would calmly tolerate all sorts of man-handling from a toddler.
Cats are pretty great.