In the Lebor Gabála Érenn (Book of Invasions) she is said to have been the mother of the cultivators Arden, Bé Chuille, Dinand, and Bé Téite. In the Middle Irish glossary Cóir Anmann ("Fitness of Names") she is said to be the wife of the legendary High King Adamair and the mother of Nia Segamain, who by his mother's power was able to milk deer as if they were cows. According to the Metrical Dindshenchas, she was the mother of Fand.
She appears in the Ulster Cycle, where she is the lover of Fergus mac Róich and the owner of a magical herd of cattle. The Táin Bó Flidais (Driving of Flidais's Cattle) tells how Fergus carried her and her cattle away from her husband, Ailill Finn. During the Táin Bó Cúailnge (Cattle Raid of Cooley) she slept in the tent of Ailill mac Máta, king of Connacht, and every seven days her herd supplied milk for the entire army. In a later version of Táin Bó Flidais she has one cow which can feed 300 men from one night's milking. Another Ulster Cycle tale says that it took seven women to satisfy Fergus, unless he could have Flidais. Her affair with Fergus is the subject of oral tradition in County Mayo.