It seems to me very little is known about the female airbenders. In his recounts of his early life with the Air Nomads, I don’t think Aang ever mentions any women; and we already know so little of the people to begin with. You see a few in clips from the show, but he only speaks of the monks. And I believe of the few past lives of Aang’s that we know of, Avatar Yangchen’s past is quite unexplored.
Also, I’m well aware of the Air Nomad Genocide, but you’d think that Aang would at least remember a nun or two.
So I’d like to appreciate Avatar Yangchen, the older-looking, unidentified nun who helped the little airbender boys choose their sky bison, and of course, Ikki and Jinora. It’s good to have some female airbenders in the show.