Her snapping is about her, so point it back to her.
"You sound like you have very definite thoughts about this. Do you want to say more."
"You sound angry. Are you okay?"
Include your own self-defense comments.
"Oh, I enjoy that job/field. But it sounds like you wouldn't" (meaning I am me and you are you!)
"Thank you for your thoughts. I wasn't actually looking for approval, just chatting! )

I have a friend who snaps too. She can snap one minute then say something entirely friendly the next. I am exploring it in therapy, seeing if my perceptions are right (is she really snapping or am I hearing it as snapping because I'm hearing criticism that might or might not be there), noticing my reactions (often a supressed rage---hello stroke!), etc.

Best of luck to you!