'Wrongful termination doesn't tend to hit the court system like you think it should unless you have hard evidence, particularly in at will states' is absolutely something I've heard from lawyers.

Discovery is a thing. Big companies are more likely to catch these shenanigans, making it automatically a legit term, and also more likely to have retention policies where you can get it later in discovery.

You're right about smaller corps.

It's not a big corp vs small corp distinction; it's a question of how important the employees in question at the company are who were in the more powerful position. A large company isn't going to bend over backwards for a seven rungs down middle manager committing the wrongful termination, but when the most influential members of the company are involved all the stops come out. It's just more likely that a small company involves extremely influential to the company employees.

Do you think this is going to work out for her?

What does "work out for her" mean?