By Gene Marks Meet Lilly Bumpus. Lilly is eight years old. And she’s sold more than 32,000 boxes of Thin Mints, Caramel deLites, Do-si-dos, and S’mores in one year. No, this is not a joke. Lilly holds the single season record for selling Girl Scout cookies. Did I forget to mention she’s eight years old? “She…