Sokka almost thinks that she might end up having a problem with Toph. With Katara and Aang sometimes they can get a little silly and immature because they're around each other. And with another younger kid added into the mix, Sokka isn't sure what would happen. But instead of it being her and the earth bender having issues, its Katara and Toph. And Sokka's not exactly sure what she could do to help the two of them get along.
That night is an absolute nightmare. Between Katara and Toph fighting and the mysterious thing chasing them, Sokka does not sleep well. Or at all for that matter. Then the girls from Omashu show up. And even though they get away, Sokka's ego is pretty bruised from Toph saying that Sokka doesn't count as a fighter since she can't bend. When Sokka realizes that they've spent the whole night getting no sleep, she's angry, but more than that she's exhausted. Appa feels the exact same say, and proves it by falling asleep while they're still flying.
As soon as they land Sokka decides to try and get some sleep, but Katara and Toph's fight keeps her awake. Sokka can't really do much to stop her so instead she focuses on helping Aang and Katara clean Appa off so that they can create a fake trail. The group splits with Aang creating a fake trail and the Water Tribe sisters looking for Toph. Instead of finding Toph, the girl in pink and the girl with the weapons find them.
The fight with the two doesn't go to well. The girl in pink is able to render Sokka's arms and one of her legs useless. If the girl in pink wasn't so busy trying to capture Sokka, the water tribe girl would want to ask her to teach Sokka her ways.
With Appa's help, the sisters are able to get away and go look for Aang.
When they find him in the abandoned town, things get worse. Sokka really just wants to sleep, but instead they have to deal with Zuko's evil sister. The princess gets away and then Zuko makes them leave before they can help. Sokka doesn't let herself worry about it too much, instead she lets herself fall asleep on Appa as they continue on their journey.