But what happens to her? I don't know, if you wanted a grim ending...
Well, Firelord Azula is a gracious leader... she awakens every day to consult the documents of government, maintaining the fire kingdom while the Phoenix lord goes about his business. It's been odly long since he returned, but she knows he's busy. Her attendents snap to at her every command, and even if the weather always seems bad, or some vital message comes in...always something that for some reason insures she doesn't have the chance to walk beyond the gate of her estate, they treat her as the fire lord should be treated. She doesn't even notice that the documents are always the same documents.
Sometimes a man drops by and they treat him with great respect...perhaps an envoy of her father? He looks strangely familiar almost as if...but no, it's been years since Zuko lived. He makes his bow to her and speaks with her Chamberlein, and then he leaves. Ah well, there is more work to do, Firelord Azula knows, as she consults maps that have military formations on them that exist...only in her mind.
And riding away, Firelord Zuko ends another once yearly trip to his sister's prison...a prison that exists primarily in her own mind. If she ever remembers, he'll have to decide what to do. But it's been a long time and she's shown no sign of that. Perhaps it's better than facing the reality.
there is just one more thing. Every year, on the anniversary of Soizins comet, Azula retires to her room...and that night, the attendents dread, because she'll start to scream and rage, against her mother, against Mai against Ti Lee...and the next morning, when she walks out, completely calm, her attendents will have to work hard to insure her totally destroyed bed chamber is ready for her that night...
okay, a bit long, but who knows-- Without help, Azula will probably stay i nthe land of the "I love me JAcket" for a long, long time.