After the 100 year war the Gaang naturally split up and every one went their own respective ways. You were never really in the Gaang but were with them for a good chunk of the way to victory and the others never let you forget. An earthbender nomad who looked way to young to be travelling alone, even if you were their age at the time, they refused to let u travel in peace and dragged you to adventure with them. Years later, after the war, you are a well known earthbending teacher but still a traveler at heart, which brought her to all kinds of places, even in the firenation where you oh (not) so unexpectedly stumbled into a bit of a problem.