“They hurt,” Lizzy said. “If you ever put Band-Aids on your nipples, those things are stiff. Any time you move around you can just feel it. It’s like an annoying, rubbing feeling, especially in a sensitive area.” She wore the bandages for 45 minutes before she began crying in class. Her best friend took her to the bathroom and Lizzy lifted her shirt to show her the bandages. Then she peeled them off and contacted her mother.

“I got a text from Lizzy saying, ‘This is not a dress code violation and I feel completely attacked,’” said Ms. Knop. She was adamant that if Lizzy had been wearing a see-through or form-fitting shirt without a bra, she wouldn’t have allowed her daughter to leave the house. “The fact is that she wore a long sleeve T-shirt that was not see-through. It wasn’t even flattering,” said Ms. Knop. “So to say she was trying to be a distraction is absolutely absurd.”

“She didn’t even tell me about the Band-Aids until 28 hours later,” she said. “She was so embarrassed.”

In a prepared statement, Braden River High School officials said that the situation “should have been handled differently.” They maintained that Lizzy was in “violation” of the dress code and that their intention was to “assist the student in addressing the situation.”

The incident happened two weeks ago — Lizzy’s initial tweet about the incident went viral — but the backlash is still going strong. On Monday, Lizzy and some of her classmates held a silent protest in support of “the destigmitization of natural bodies.” Despite threats of disciplinary action, about 30 female students opted not to wear bras, and a number of students decorated their backpacks with Band-Aids in the shape of an X. One student wore a shirt that read, “Do my ni**ples offend you?” (The asterisks were hers.)