Sinead's lips compressed slightly in embarrassment as she realised her mistake- well, that was what she got for speaking on autopilot like that. Still, everyone had been there, right?
"Yes, thank you, Sir," she replied, trying to peer surreptitiously at his box- maybe the mist would be lifted in there and she could see what they were actually working on today? Whatever it was, it seemed a lot more exciting than last time, and she was glad she'd showed up.

This suspicion was only confirmed as he began to speak. She nodded along almost unconsciously to his words- she absolutely knew how to conduct herself around potions, even if creatures weren't her favourite. As soon as the mist lifted from the boxes, her face lit up with interest- she knew exactly what the creature was, and she'd read a bit about them in her Care of Magical Creatures textbook. Actually, healing was pretty interesting in general- she might have heard about them from some other source as well. Hand shooting up into the air, she spoke as soon as River indicated she could, face intent with recollection.
"They can have a dangerous bite, I don't think it's fatal, but it causes a reaction. And their tentacles are valuable, because they can be used for potions, usually healing potions for cuts? Can you use their venom for potions as well?" She couldn't remember reading anything about that, but she knew that plenty of animals' venom was useful in potions, so it kind of stood to reason that the same might be true of a Murtlap.