True. If you got two kids (I do) one can just look for both while the other one can have their shower/toilet/sleep whatever. Actually we are often taking turns sleeping.
Even larger communities. I don't think nuclear family is actual the natural state for our species. But recent invention.
Things start to scale much better once you get to bigger family units, with 3 or even 4 generations present. Grandparents, uncles, sisters and brothers of different ages. Looking after the kids. Or in tribal society whole tribe up to 100 people.
