She's picking things up as she goes. Clearly she didn't know the demon as much as Peter. but she was at least starting to get an idea.

"Oh! Well, good! I mean, if you don't mind layering up, we can go...swimming!"

Cold water was going to be painful, but Luz had certainly been through worse.

"Sure, we can fly together too! You prefer me on my staff, or would you like to see me as a bird?"

Yes, you heard right. Clearly Luz wasn't going to begrudge Paimon and indulge today.