I've found that people who behave like that are usually hoping I react so they can run tell on me. So I never, and I mean never, give them what they're after. I'm great at "Ummm..." and "Yeah..." It infuriates them because they look stupid trying to have an argument with someone who refuses to participate. Sometimes they raise their voices, attracting attention, and the rest of the room looks at them rolling their eyes and wondering why they're so worked up. They're the same ones who ask you for your opinion of another coworker and then go tell that person what you said about them even if they themselves said negative things. I've been alive a long time and I know what those kinds of people are trying to do.
She wants a reaction. Don't give her one.