Who is Hattie Mae Harper Macke from Moon Over Manifest and what is their importance?

Hattie Mae is a young writer, who invents a column for herself in her uncle's newspaper after she graduates from high school. Her column proves to be invaluable to Abilene, as she listens to Miss Sadie's stories, which reinforce much of what Miss Sadie tells Abilene. Hattie Mae supports Abilene's attempts to find the spy known as the Rattler.