With pastel hair bows, YouTube youth take on mean girls

THIRTEEN-YEAR-OLD JoJo Siwa rolled up to school in a souped-up vintage car with a giant pink bow plastered on the grille. Inside the car, with her blond hair tightly pulled into a side ponytail and wrapped in a pastel yellow bow, she sang to her mother, I don't really care about what they say, while a group of mean girls wearing not-so-pastel clothes snickered from a bench. (We know they're mean girls because the words "mean girls" are displayed on the screen next to them.)

"Don't let the haters get their way," JoJo's mother, also clad in yellow pastel, told her.

No worries. The new young teenage heroine of suburban America showed no fear. After winning a rowdy dance battle in her video Boomerang…