Who is Mary Luther from The Dry Grass of August and what is their importance?

Mary Luther is a 48 year old African-American widow. Mary has worked for the Watts family since 1946 when Jubie was only five years old.

"Mary came to work for us when I was five, the first colored person I've ever known." (Chap. 3, p. 31)

Jubie was fascinated by Mary and eventually became very close to the woman. Jubie, who is 11-13 throughout the majority of the book, views Mary as a part of her immediate family, despite the color barrier.