Okay, we're just going to call it here and now: Abilene is the protagonist. You could make a case for Jinx, but the story about Jinx is bring told to Abilene. She's the reason we get to hear it at all and the reason we have access to Ned's letters and Hattie Mae's articles. And she's the one who ends up saving the day for everyone in the end. Convinced?