Iio

History
As a Mother Superior, Sister Iio was the female Airbender nun in charge of the Eastern Air Temple seen in a flashback during Appa's Lost Days. She prepared several children, including Aang, to bond with a group of young Flying Bison. She gives each of them an apple, telling them how to choose a bison carefully, because 'a Sky Bison is a companion for life'. Her ultimate fate is unknown, though she likely died when the Fire Nation destroyed the Air Nomads.