The children were fighting for their lives and more cultists were pouring through the portal. She flashed back to the fight with the cultists at the midnight hotel, the fight where Zuko had been tainted. She couldn't allow that to happen again, but she hesitated at Zuko's words.

He's injured, She replied, You and Katara must get to him. I'll hold them off. She was only thinking of getting them out of danger before they could be tainted, but she had to be rational about it. If you can get him close enough to me, I can carry the three of you back to the city. I'm faster than they are.