If we allow our one-and-a-half year old to "help" us fold laundry he will learn something about buttons, zippers, snaps, where things go, the physical properties of cloth, what happens when you drop it, how easy or hard it is to carry compared with everything else he has ever carried, what clean clothes smell like, how a big towel can turn into a small bundle, how the small bundle you just folded can turn into a big towel again, plus any songs we care to sing or stories or related or unrelated facts we care to pass on.
I think Buffy was a grown-up. One of the amazing things about the show was that I was able to grow with her. Yes, she started in high school, and then she went to college, and then essentially she was a mother to all the other Slayers, so I always felt like Buffy was a grown-up.