Child Abuse, the Pastel Years.
If you see a movie set in 1976, you probably won't see anyone wearing pants like these. No one would believe it. Oh, you're exaggerating. They couldn't have been that ugly, or kids would have refused to wear them.
Hah. Tell them they're the latest stylish thing, and some will wear them; if she has enough social juice, everyone else will want to wear them.
She can ruin it for everyone. But when it comes to the fashion victims, remember: everyone's a volunteer.