Why douse opal call her dad the preacher not dad?

Opal calls her dad "the preacher" as a reflection of his role and identity within their community. This nickname highlights his commitment to his faith and his responsibilities as a minister, which shape her perception of him. It also signifies a certain distance or formality in their relationship, emphasizing the distinction between his public persona and their private family dynamic. This choice of Words encapsulates both admiration and the complexities of their bond.