If she is exclusively meant to give texture to Arya's character why she has more chapters than BRAN THE FIRST CHARACTER EVER CREATED STARK?
Mainly because - as GRRM has mentioned several times - Bran is a very difficult character to write and the most magical character compared to characters like Tyrion whom GRRM loves writing for.
Bran has so few chapters because his is the most important POV, is the POV with the important magical/fantasy component that underpins the entire series - the threat from beyond the Wall - and GRRM needs to handle it carefully.
There's Time Travel involved and as any science fiction/fantasy fan will tell you that's one of the hardest concepts to successfully land in a story. There's problems like causal loops and temporal parodoxes like the Grandfather paradox, which GRRM, IMO, was planning to resolve by having Bran's consciousness travel instead of his body.
Keep in mind that we haven't even got to the Hodor scene from the TV show which happened I think in 2015!! And which D&D have said multiple times is from the books.
In other words, it's easier for GRRM to write Sansa Stark organizing feasts in the Vale and describe the food and Brienne wandering the Riverlands looking for a maiden than spend time writing a complicated time travel subplot for Bran Stark.
This is also why the books have barely moved in plot because like a typical procrastinator GRRM spend his time writing the easier traveling monologues while Bran is stagnating beyond the Wall and GRRM is finding it harder and harder to write the fantasy/magical aspect of the story -
"Now it's harder when you're talking about dreams and you're talking about other types of magic, how do you handle it? Well… It's tough. It's not easy. I uh… People have sometimes asked me, which is the easiest character to write in my series, which is the hardest character to write? The easiest for me has always been Tyrion Lannister because, I don't know, he's fun to write. He's a smart ass. He gets into very dramatic situations. The hardest to write is Bran. Uh Bran Stark, who is the character who is MOST involved in the magical side of it. And I have to be… he's also the youngest character, so it's also hard to write from the viewpoint of an 8 year old, because I'm actually a little older than that. You have to think, what he would know, what he would not know, what he would understand, what he would misinterpret. Um. But then there's the magic! And how do you handle the magic? Um. All I can say is it's something that does require a lot of thought."
George R. R. Martin Answers Fan Questions
"I had a very hard time, a struggle, with writing from Bran. Because Bran, of all the characters, was the one who was most involved in magic. And I think magic in fantasy, sorcery, the supernatural, all of these things have to be handled with a great deal of care, or they can overwhelm the story. So, I rewrote some of those Bran chapters over and over again."
Bran will have one or two chapters in ADwD, where otherwise he would have been left out of the what would have been the fourth book entirely. He remains one of the most difficult POVs to write due to his youth, crippled status and the magic.
In the above 2005 SSM he also talks about the 5 year gap and how it affects the children and he keeps talking about Bran and Arya - never Sansa. It's clear that for GRRM it was important for Arya and Bran having a 5 year time jump. Sansa was never even a consideration when GRRM was crafting the story and ran into obstacles.
If she is just a cam why does she has a profecy still to complete that was mentioned in ARYA ONE OF GEORGE FAVE CHARACTER STARK? It is senseless and pure cope.
Prophecy still to complete? Everything that the Ghost of High Heart talks about happens in or before ASoS.
“The old gods stir and will not let me sleep. I dreamt I saw a shadow with a burning heart butchering a golden stag, aye.” - Renly (Happens in ACoK)
I dreamt of a man without a face, waiting on a bridge that swayed and swung. On his shoulder perched a drowned crow with seaweed hanging from his wings - Euron (Happens in ASoS)
I dreamt of a roaring river and a woman that was a fish. Dead she drifted, with red tears on her cheeks, but when her eyes did open - Lady Stoneheart (Happens in ASoS)
I dreamt a wolf howling in the rain, but no one heard his grief. I dreamt such a clangor I thought my head might burst, drums and horns and pipes and screams but the saddest sound was the little bells. - Red Wedding (Happens in ASoS)
I dreamt of a maid at a feast with purple serpents in her hair, venom dripping from their fangs - Sansa/Purple Wedding (happens in ASoS)
And later I dreamt that maid again, slaying a savage giant in a castle built of snow - Sansa tearing apart SweetRobin's doll in the snow model of Winterfell (happens in ASoS)
So basically EVERYTHING the Ghost of High Heart mentioned has ALREADY happened. Renly's death is old news by the time she has her vision. It's not exactly prophecy but some visions that the Ghost has.
Sansa's so called 'prophecy' is complete. The giant is SweetRobin's doll in a castle 'built of snow' - it could not be any more clear that this is the castle of snow that Sansa was building.
"if she was important GRRM wouldn't even think about kill her" honey, GRRM killed Ned in the book in which he was so central that most people thought he would be THE MAIN CHARACTER.
I would say that Sansa has become important now because she is dealing with Littlefinger - one of the most important human antagonists of the series, responsible for the downfall of the Starks. If Sansa manages to play a role in his downfall that's a big deal indeed.
However, I would also say she is one step below the tier one - central 5 key characters - in the series and yes, any character can die as GRRM mentioned in his OG outline to his editor -
Old characters will die, and new ones will be introduced. Some of the fatalities will include sympathetic viewpoint characters. I want the reader to feel that no one is ever completely safe, not even the characters who seem to be the heroes. The suspense always ratchets up a notch when you know that any character can die at any time.
Five central characters will make it through all three volumes, however, growing from children to adults and changing the world and themselves in the process. In a sense, my trilogy is almost a generational saga, telling the life stories of these five characters, three men and two women. The five key players are Tyrion Lannister, Daenerys Targaryen, and three of the children of Winterfell, Arya, Bran, and the bastard Jon Snow. All of them are introduced at some length in the chapters you have to hand.
Hope this answers your questions.
