Hmm. She didn't expect that. The telling anyone that if they didn't want to be here they could leave bit wasn't surprising, but moving on with the lesson without threatening to give out detentions or worse was surprising.

Arya wouldn't be leaving the class. She apparently needed the class for whatever job with creatures she obtained after graduating Hogwarts. Silently the girl continued to work on her potion, pausing only to take notes and listen to the students who continued to ask the woman questions.