How does Judy Dark ger her superhero name in the novel, The Amazing Adventures of Kavalier & Clay?

Luna Moth is a comic-book character that Joe invents to celebrate his relationship with Rosa Saks. In the comic-book, Judy Dark, a librarian, is inducted as a superhero by the Goddess of Lo. Joe decides to call the character Luna Moth, after the moths that he finds on Rosa's bed in her room and studio.