Who is Agnes Tsosie from Talking God and what is their importance?

Agnes Tsosie is an older woman, and the matriarch of the Bitter Water Dinee (a Navajo clan). During her lifetime, she has served on the Navajo Tribal Council twice, and played a large part in acquiring the legislation for wells to be drilled, making water available at every Chapter House. Tsosie's photo once appeared in National Geographic.