When Katara confronts Toph about the wanted poster, she's barefoot, but moments later, in a more distant shot, she's wearing sandals. See more
[Writing a letter
"Dear Katara, sorry for everything. Your friend. Toph."
[Sokka puts the letter in Hawky's messenger pack. Then Hawky flies to Katara
I know this is from you, Sokka! Toph can't write! Ugh! You're all driving me crazy!
[Katara storms off
I can't believe we forgot Toph can't write.
Yeah. We're idiots.