The minute Zuko barked an order at her, Katara tightened her grip on the crossbow and debated exactly how many steps she'd have to take before she'd be close enough to hit him over the head with the thing. Then his tone changed and she forced herself to do as he'd said.
Her right hand went to the trigger and she gripped with the left hand, frowning in thought as she studied her hands. She'd never realized she used her right hand more forwardly when bending before. The fact that he had noticed both impressed and irked her. Although perhaps that was why Angel had wanted him to train her? Clearly, he knew at least something about her movements, which hand she preferred, and likely a half dozen other little facts which would come in handy when showing her weapons she was wholly unfamiliar with. So, while she may not like the prospect of having to learn anything from Zuko, from Angel's point of view she supposed it made sense in a way.
Though she still had every intention of explaining to both the vampire and his Seer what 'I don't want to work alongside Zuko unless there is no other choice in the matter' meant, just as soon as they returned.
With a slight shake of her head to get her thoughts back on the situation at hand, she raised her gaze and sought out Zuko once more. "There. I'm holding it right. Next?" she questioned. Okay, that was a little harsher than even she'd meant for it to sound, but really, what did he expect? He wouldn't be any happier if the situation was reversed. In fact, she would probably have already had a face full of fire and he would have stormed off in a huff. At least she was still here. That said something, right?