[Katara blinks] To make ice? I can make ice out of anything, but how strong and how thick it is depends on what's available.

[And Katara decides to demonstrate. It's a bit painful to use the techniques that Hama taught her, but this still was one of the coolest things she'd ever seen a waterbender do. It's uncomfortable for other reasons as well... but Nami should her her weapon. Fair was fair. She moves her hand in a slow circle in the air and pulls from the moisture there. A thin layer of ice coats her three dominant fingers - she hadn't pulled all that was there, there was no need to push, and she wasn't going to be slicing anything as Hama had.] You see?