Disclaimer; I do not own nor did I create the Avatar universe or any of the original characters. The only characters that are of my own creation are those not used in the show or comics. There will be some changes to the show's plot, details, and timeline.
Aang and Toph - 14/15
Katara, Azula, Aelita (OC) - 15/16.
Sokka and Zuko -17/18
The others around them are of similar ages. The age change is to help the story flow and work better with the overall more mature themes/nature.
Aelita = eye-lee-ta
Some chapters will include cursing, mature themes, and languages. Read at your own discretion. A few episodes will be a little out of order, it won't affect anything heavily, just helping further the plot better. There will also be occasional small chapters that will take place essentially between episodes to add more depth to the characters and clear up details.
UPDATE:
If you're a long-time reader and you've just come back for more, you deserve a gold star, because my writing has come a long, LONG way since we started this journey in 2020.
If you're a new reader, you still deserve a gold star because when I look back to the start of Book One, I just have to chuckle when I see the way things have evolved with my own eyes. I have a lot of love for Book One, it's where Aelita was born, but I have even more love for Book Two, and Book Three is currently my baby.
With that said, welcome to the wild ride! Be sure to add Book Two: Carved in Rock and Book Three: Forged in Fire to your libraries so you can follow along with Aelita's story, because I might be biased, but I think its a good one.