Sara Snow was supposedly the bastard daughter of Lord Rickon Stark.
History[]
According to Mushroom, Jacaerys Velaryon, the Prince of Dragonstone, fell in love with Sara when he visited Winterfell to secure the support of Lord Cregan Stark, Sara's half-brother, for the cause of his mother, Rhaenyra Targaryen, during the Dance of the Dragons. According to Mushroom, Sara and Jacaerys slept together, and Cregan flew into a rage when he found out, though Sara assured him that they had wed beforehand, speaking their vows in the Winterfell Godswood before they had sex in the snow.
Archmaester Gyldayn puts little faith in Mushroom's suggestion that the two were married, going so far as to doubt Sara's existence, claiming that it would be out of character for Jacaerys to break his eleven-year betrothal to Baela Targaryen. Gyldayn does concede that it is possible Jacaerys may have slept with Sara, if she even existed.