The book flashes back to when Rachel is driving to ride the buses with Beth for the very first time. She passes a familiar stretch of highway—years before, she was driving here with Sam and Beth when smoke started coming out of her car. They pulled over, got out, and ran to a patch of grass a safe distance away. While Sam returned to the car to wait and see what would happen, Beth and Rachel sat on the grass, leaning on one another. “Iz gonna be all right,” said Beth.
In this scene, like when she told her father “at least we have each other” when they got lost on their way home, Beth ends up serving as the voice of reason during a crisis. In this way, Beth’s disability is really like a superpower: it allows her to see basic truths that other people overlook precisely when they most need them. Of course, Rachel uses this chapter’s brief anecdote to symbolize her reconciliation with Beth after their fight. “Iz gonna be all right” is a way of saying that Rachel and Beth will always work through their problems together—even if they grow distant at times, their love will reunite them. Nothing can ever destroy their sisterly bond.