I believe they should be able to talk about this shit outside of the classroom. Obviously if she brings her agenda/racist bullshit into the classroom, she should be fired. But holding offensive views alone shouldn't get you fired unless it affects work.
I know its easy to naively assume that she must also be a piece of shit in the classroom, but you'd be surprised at how well some people can compartmentalize things. My highschool had a biology teacher arrested for owning hundreds of snakes that he was using to make homemade medicine. Turns out he was some crazy super-fundamentalist Christian cultist selling homemade medicine to other cultists. No one ever suspected a thing from him though, because he seemed like the most normal person in the world at school. He just knew when to switch the crazy on and off.