Sara Snow

A bastard daughter said to have been gotten by Lord Rickon Stark, father of Cregan, on a woman of Winterfell's household, and thus half-sister to Cregan the Old Man of the North. Mushroom's Testimony claims that during Prince Jacaerys Velaryon's visit to Winterfell in 129 AC, the young prince became enamored of her, and that the two were wed in secret before a heart tree, with Cregan looking on, in a ceremony that bound Stark and Targaryen blood years before the Pact of Ice and Fire was sealed in writing. No other source agrees, and most maesters at the Citadel hold the tale a fool's fancy; Sara's name appears in no other chronicle of the north.