Yeah, people do that. Couple of possibilities:
One, she doesn't actually feel the way she said and was just venting.
Two, an error in communication. It would've sounded stern but kind to her ears and RAEGRAGEBEASTHATERAGE to yours. It happens. Especially since 'condescending' is so easy to inflect in your tone when you're trying to sound genuinely caring.
Three, she's trying to save face.