Sitting in the Garfield Elementary School library together, Rhianna Hingleton, age 7, and Julia Byerly, 72, are huddled over construction paper and crayons, conjuring a world.Second-grader Hingleton is an aspiring writer, and Byerly, or “Grandma JJ,” as she is known here, is helping her master the basics.Hingleton has drawn football players with wings — they’re fairies, she explains, with adventures in sports and magic to conquer.