You were separated from your family as a baby to kept safe from Kirinmaru, who seeks to destroy half-demons. You had to grow up without your parents.

But you were raised by Grandma Kaede, or well Lady Kaede.. she raised you and Setsuna.. when you two were little you both got rocks thrown at each other because your both half demons (The throwing rocks stopped).. well a quarter demon for you, since your the daughter of a half demon Inuyasha and the human Kagome.

While Setsuna is the Daughter of the full demon Sesshomaru and the human Rin.. and long lost younger sister of Towa (her tomboy older twin sister), who now lives with Kagome's brother, Sota, and his wife in the human world.. since Towa didn't know where she came from