> Sounds like a lawsuit incoming. <
If so, she will lose. The First Amendment protects free speech. But the 1A only protects you against the government. It does not protect you against your employer.
As an extreme example, suppose you work for Ford. And you are standing on a public sidewalk in front of a Ford dealership. And you are holding a sign saying “Ford has bad management.”
The police cannot legally arrest you. That would violate the 1A. But Ford can legally fire you. Heck, Ford can legally fire you for anything you might say.
The only exception would be if you were working under a contract that prohibited such a firing.
On what grounds.