She wasn't being a 'brat' she Lost her mind. Du think Zuko was the only one badly affected Von the family drama? She had nobody but Ozai- who corrupted her into being a weapon. She had no love. She's also only 14.
Zuko had her committed to a mental institution, and in the Kürzlich graphic novels "the Promise" and now "the search-part 1" Zuko saw to it that she was well cared for. In fact, in "the Suchen part 1, Zuko has her released from the institution to Mitmachen him in searching for THEIR mother. Unfortunately we see her still behaving "badly" and having delusional conversations with Ursa.
