The first full moon after The North Pole (The only name they can agree on to describe that particular chain of events) sees Aang and Katara and Sokka lying awake at night. They don't need speech, but they don't need to pretend to be sleeping, either. None of them know who the last to fall asleep that night is.
Every night, Sokka dies just a little bit more. Katara and Aang love him like the big brother he is, but they also know the pain of losing a loved one. They wait, unsure.
Sokka doesn't notice, but Yue does.