Chronicle of a Death Foretold
In the earlier published Targaryen family tree as found in The World of Ice & Fire, Princess Daenerys did not exist. In her place was Prince Aeryn Targaryen, Jaehaerys and Alysanne's sixthborn son who died young. Besides Aeryn having been exchanged for Daenerys, several other children of Jaehaerys and Alysanne were shifted in their order of birth.
Regarding these changes, Elio Garcia has stated the following:
... George had some new ideas for some of the names and the stories of the children who died young, and corrected some issues that came out of his original birth order (we actually got the names of all the kids quite late in the production of TWoIaF—literally a month before we had to finalize the book—so there was not much time to interrogate it). However, the stories of those who live to adulthood, as published in TWoIaF, do remain the same (just, of course, much more detailed).
Jaehaerys loved all three children fiercely, but from the moment Aemon was born, the king began to speak of him as his heir, to Queen Alysanne’s displeasure. “Daenerys is older,” she would remind His Grace. “She is first in line; she should be queen.” The king would never disagree, except to say, “She shall be queen, when she and Aemon marry. They will rule together, just as we have.” But Benifer could see that the king’s words did not entirely please the queen, as he noted in his letters.
It was the hour of the owl when Queen Alysanne was awoken by her daughter shaking her gently by the arm. “Mother,” Princess Daenerys said, “I’m cold.”
There is no need to dwell on all that followed. Daenerys Targaryen was the darling of the realm, and all that could be done for any man was done for her. There were prayers and poultices, hot soups and scalding baths, blankets and furs and hot stones, nettle tea. The princess was six, and years past being weaned, but a wet nurse was summoned, for there were some who believed that mother’s milk could cure the Shivers. Maesters came and went, septons and septas prayed, the king commanded that a hundred new ratcatchers be hired at once, and offered a silver stag for every dead rat, grey or black. Daenerys wanted her kitten, and her kitten was brought to her, though as her shivering grew more violent it squirmed from her grasp and scratched her hand. Near dawn, Jaehaerys bolted to his feet shouting that a dragon was needed, that his daughter must have a dragon, and ravens took wing for Dragonstone, instructing the Dragonkeepers there to bring a hatchling to the Red Keep at once.
None of it mattered. A day and a half after she had woken her mother from sleep complaining of feeling cold, the little princess was dead. The queen collapsed in the king’s arms, shaking so violently that some feared she had the Shivers too.”
—Fire & Blood - Volume I
Standing before the Iron Throne, Dany steps forward and kisses the man she loves. A perfect kiss, an expression of pure love and passion.
We push in on them until we’re tight on their faces -- their eyes closed, his hand behind her head, her hand on his cheek.
Dany’s eyes open suddenly as she draws a sharp breath.
Jon’s eyes open as well, already filling with tears. For a moment, neither moves, as if moving will make this real.
In a wider angle, we see Jon with his hand still on the hilt of the dagger he just lodged in Dany’s heart.
Her strength leaves her and she collapses to the marble; he keeps her in his arms as she falls, kneeling down to the floor beside her.
He looks down at what he’s done. Terrible. And necessary. He hopes for one last moment with her.
But her eyes are already glazing over. Winter has come to the Throne Room. Dany lies dead in his arms, Pieta-style, as the snow drifts down.
—GAME OF THRONES "The Iron Throne" - Written by David Benioff & D.B. Weiss - Based on A Song of Ice and Fire by George R.R. Martin
WELT: Again: We know what will happen to the Mother of Dragons. How do you want to surpass that in a novel – with an alternative literary version?
GRRM: Counter question: How many children did Scarlett O'Hara have? In Margaret Mitchell’s novel “Gone with the Wind” she had three children. But in the cinema version of the novels she only had one child. Which version is the only one valid - the one with one or the other with three children? The answer is: neither. Because Scarlett O'Hara never existed, she is a fictional character, not a real person, who would have had real children. Or take “The Little Mermaid”. We know her from the fairytale of the same name by Hans Christian Andersen and from the Disney movie. Which one is the true mermaid? Well, mermaids do not exist. So you can chose the version that you personally like the best. Changes are inevitable in this process. Even if the adaption is as faithful to the literary source material as it was the case with “Game of Thrones”.
—GEORGE R. R. MARTIN “Die Leute kennen ein Ende – nicht das Ende” - WELT 2020 - (Translation)
Q: It is my impression that there are parallels between Westeros history and current events in ASOIAF. so in your opinion to what degree is George martin's history cyclical? Because we have a lot of parallels. For example with the current history and the dance of the dragons.
Elio: You know George even uses that line from talking about the the arms of house Toland, the dragon eating its tail, but it was from the Archmaester Rigney which is a reference to Robert Jordan the writer of the wheel of time, that history is a wheel or time as a circle. I think George certainly deliberately sees, creates parallels. I mean this is a very obvious example, you know if you read The World of Ice and Fire, you saw the family tree of the Targaryens, and the family tree for Jaehaerys and his offspring changes quite a lot when fire and blood comes out. Because George realized that he wanted to create a kind of parallel by introducing another Daenerys. and he said like, i like the symmetry of it, I like the the sort of the way. You could perhaps read it as reflecting on Daenerys's story, maybe. I wish it was true. I mean I think fans of Daenerys need to be really worried about what's going to happen to her. Although I guess Game of Thrones maybe has revealed kind of where things may possibly end. Again the journey is going to be very different. I think you know circumstances, things are going to be very different. So there's a journey that matters. But in any case, so yes I think George uses cycles and things a bit. He likes setting up parallels of events, he likes paralleling characters, he likes paralleling events, and he likes paralleling the past and the present as well.
Linda: I think certainly that when he fleshed out the details of Fire and Blood, even when he first did the sidebars for The World of Ice and Fire, and they just grew. We could see that, okay here he's looking at foreshadowing or commenting on current events by doing a similar scenario in the past and he definitely likes to play around with those aspects.
(*) Thanks to @istumpysk and her friend for sending me this link!