"Toxic" isn't actionable. It's a Millennial/Gen Z buzzword for "I don't like this but can't be specific as to why."

Having opinions you don't like isn't actionable either.

Document everything negative they do. Anything that violates student code of conduct or band handbook - write it down, document, and be prepared to defend yourself. Be objective, be factual, and be clear. Any violations of classroom rules - document, document, document.

Don't give them punishments or exclusions that you don't already give other students. That's singling out a student, and if they're SpEd or 504, you can get in huge legal trouble for that. Follow the steps of the disciplinary process outlined in your campus handbook to the letter.

Document everything, communicate everything to her parents, and then simply leave her off your approved list for next year. You can cite your mountain of documentation of behavior issues as for a reason why.

There's five weeks left. You can put up with it that much longer if you've put up with her this long.