Katara felt her stomach drop sharply and glanced from Zuko to Angel and back again. Zuko really shouldn't have commented on the knocking - this was Angel's hotel, after all - but at the same time, Angel wasn't their father. Their boss, yes. Not their parent. He didn't have a right to act as though he was.
Being told to go upstairs made her eyes widen slightly as she quickly looked back to Angel. Had he just called Zuko a princeling? Any second now she expected the vampire to burst into flames and, honestly, would be hard pressed to really hold it against the Firebender. When that didn't happen, however, she found herself... impressed. Apparently, he really was trying. Which meant she knew what she had to do.
Drawing in a steadying breath, she exhaled slowly. Then she straightened up slightly, raised her chin, and stared directly at the vampire with a soul as she gave her answer in a firm, unyeilding tone.