That is a practical request to help avoid damaging the rubber surface of the playground. High heels would punch holes in that surface, dramatically shortening its life, reducing its protective capabilities, and likely even twisting/snapping an ankle if the heel remains jammed in that rubber and the wearer is moving quickly.

Definitely a fan of Levi’s, especially the high-waisted models. I intensely dislike the feeling of my pants being about to fall off, so low-waisted is out. The 516 is my favourite, although I also have 541s, 501s, 505s, and 550s.