The 16-year-old singer is facing criticism from some who say it's hypocritical to perform for an administration that doesn't support her transgender sister's rights.
The student responded with a scathing letter to University of Wisconsin Chancellor Mark Mone, in which she asked, "Do you have any fucking idea how hurtful this is?"
The school district is challenging an order by the Obama administration to allow restroom choice for transgender students, arguing it jeopardizes students' privacy rights.