Sara Snow

Mushroom places Sara Snow at Winterfell when Prince Jacaerys Velaryon arrived there seeking Lord Cregan Stark's support for the Blacks during the Dance of the Dragons. It was then, by his account, that the prince noticed her.

Jacaerys spent a night with Sara, and when her half-brother learned of it, he flew into a rage. He only calmed down when she swore the prince had made her his wife: by her account, Jacaerys had spoken his vows to her beneath the heart tree of Winterfell, with only the old gods as witness.

Maester Gyldayn admits the tale is captivating, but he does not believe it. He finds it strange that Jacaerys would break his betrothal to Lady Baela Targaryen for a northern bastard, something that does not fit what he knew of the prince's character.

He goes further and questions whether Sara Snow ever existed at all. He allows that, had she been real, a single night together would be plausible enough; a marriage, though, strikes him as absurd.