She is voiced by Lisa Edelstein, who is famous for her role as Dr. Lisa Cuddy from House.
Kya is the youger sister of Bumi and older sister of Tenzin. She is the only waterbending child of Aang and Katara, As Tenzin is an airbender and Bumi was at first a non-bender until after Harmonic Convergence, where he became an airbender.
She had always felt a stronger connection with her mother as a waterbender.
She is named after Katara's late mother.