The Answer Is In The Comics.In The Search Zuko And The Others Find Her But She Has Lost Her Memory While She Has A New Husband And Kid.In Smoke And Shadow Zuko Brings Her Along With Her Family In The Fire Nation Capital !!!!
Wasn't there a comic book about Zuko and Azula going to find their mother with the Gaang? I think she ended up being with this guy she'd fallen in love with before she met Ozai... I honestly don't remember the details but I think that's what happened. And Zuko was really that guy's son and not Ozai's..?