District IT policy prohibits teachers from connecting their phones to the school wifi network (along with many other frivolously absurd IT policies).
For three years, I have sent email to various administrators, including to the school superintendent, pointing out how dangerous it is for teachers to have no cell signal, especially if there is an emergency such as an active shooter or whatever. Beyond a polite response promising that it'll will be "looked in to," nothing has come of my messages.
Last week, teachers across the district were told that they are soon to be required to use 2FA using their personal cell phones to authenticate to the school network for email, grading software, etc.
I have no idea how this will be able to work at her school.