Her arms, weak with age and illness, cradled the baby that had been placed in there. It was tiny, only having been born hours ago. She let out a low, quiet sigh.

She had been counting the hours until they reached this one, number three. Years ago, after her first great grandson had been born, she had received a dream of an experience she had long forgotten. The day, insignificant when first remembered, was one of the days she had spent traveling with her late husband before the end of the war. They had yet to even reach the Northern Water Tribe, both of them still low level water benders. They made a pit stop in a village, chosen because it seemed to hold a skilled fortune teller. She had visited the lady, Aunt Wu, several times. The specific time she remembered told of how she would die. She considered it a nice death at the time, for it took place after a long prosperous life, but now that life was painfully long, and she wished it's end had come sooner.

Her husband, Avatar Aang, had died many, many years before. Even before their first grandchild had been born. Here she was now, holding their third great grandchild. She had lived too long, far too long, without him.

Katara offered the child back to its beaming father, her face losing even more of its color, an almost impossible feat. She blinked, her eyes flickering open and closed tiredly, before speaking in an old, old voice, "The boy is beautiful, he will be a great man some day. Now please, leave your grandmother to get her sleep."

Then, the tired waterbender closed her eyes. She fell into a deep sleep, her dreams carrying her off to a distant world where her years melted away and her love pulled her into a strong embrace, helping to ease her transition.

She did not wake again.

Instead, she held his hand and began the never ending journey into the world of spirits.

And thus, a prophecy that had been made decades before was fulfilled.

...

So, I was recently rewatching all of ATLA, and I ended up watching the episode The Fortuneteller, in which there is scene where the fortuneteller describes how Katara will die. That's what you just read, because I couldn't let it rest. All of her fortune (that we heard) followed along with what has happened already in cannon, (If you consider LoK canon.) so I just went along with it and ended up with this. I'm sorry if you find Katara's thoughts out of character, I tried my best.

Love ya! - The Goddess of Myths