This is exactly the kind of response with the right amount of flippancy/belligerence that "they aren't/weren't forced to sign" deserves to be met with.
FWIW I agree about not enforcing non disparagement clauses but legally that not the world we live in.
That's not how it works at most companies.
It's a free market! If she didn't like the offer, she could've just gotten herself fired from some other company instead. /s
If non disparagement clauses were illegal then perhaps the severance amounts would be smaller since there’s now much less value to the company.
If someone gives you the option to accept $ to sign a contract agreeing not talk about something that is legal but morally bad, and you say yes, then talk about the thing, you will correctly be losing the lawsuit, no matter how bad the thing is.