Hello,
I got to thinking not to long ago that Katara was probably the next in the cycle of the Avatar had Aang not run away and dissappeared. Why? Because:
1) At the beginning of the series Aang ran away but got lost in the safety of the South Water Tribe area Was it his past lives that brought him there?
2) In the avatar cycle if you watched the first episode of book 2 you see about 10 of Aangs past lives and it seems to go into a pattern of boy boy girl girl boy boy girl girl(Kyoshi) boy(Roku) boy (Aang).
3) Aang is an airbender-the next element in the cycle is Water.
4) Katara was the only waterbender in the Southern Water Tribe (at the time)
5) Katara quickly (if you will) with dedication and determination became a Master of Waterbending and was quick to learn it. A natural thing -just like aang was superior with his airbending skills before he learned he was the avatar.
6) Katara was born 100 years from Aang-if Aang had fulfilled his purpose and died whenever it would seem like a logical explanation
7) When They found Aang, Katara was 14 if she was next in the cycle and things had gone the way they were supposed to (without aang running away and without the fire nation), Katara would only have 2 years to learn she was the next avatar.
What do you think?