[jyl]

State law may say a CHL holder is permitted to bring a gun on public school property, but that doesn't mean the school is required to continue employing that person.

Analogy - you have the legal right to view adult websites, but your employer can terminate you for doing so at the workplace. You have the legal right to bear gang tattoos, but your employer can terminate you for having them. You have the legal right to drink alcohol, but your employer can terminate you for drinking at work. And so on.

Basically, if you are an at-will employee, your employer can terminate you for pretty much any reason or no reason, as long as it doesn't violate specific labor and anti-discrimination laws. If you have an employment contract or union contract, you may have additional protections.

I'd bet she loses. Unfortunately.