She got banned from the 火災, 火 nation because she killed firelord Azulan. And she did that because Ozai was going to kill zuko so she had to kill Firelord Azulan to save zuko. Also あなた can know a little of what she did watch 日 Of Black Sun Part 2 when zuko is talking to his father. But they should make a special episode where they 表示する zuko finding his mother または she goes back.
