Urstin is an unknown cousin, once removed of the Archeron sisters. It is unknown if she is still alive.
Urstin is the cousin of Feyre's mother who lived on the Continent. When her cousin died, Nesta sent letters to her to help them financially, but her pleas went unanswered. It is unknown if Urstin is still alive, as Nesta believes she is still living on the Continent while Feyre believes she died from a disease.
Powers and abilities
Cousin to the Archeron family, but not close enough to help Mr. Archeron and his daughters from falling into poverty. She ignored letters for help.