On the way to the grocery store today, I asked Kaia what kinds of things she thought big sisters taught their little brothers. She happily started listing all sorts of things, such as "don't hit", "don't bite", "don't go into the street alone". All good things. Then she said:
"And I'll teach him not to tear the leafs from trees, because the leafs clean the air!"
His education will be well-rounded, thanks to his sister.