Evelyn Gaines (also credited as Lynn Lovelace and Lynne Evans) was a writer for All-American Publications, one of the studios which supplied DC Comics with their stories. She wrote such features as Hop Harrigan, Little Boy Blue, and Mr. Terrific.
Her uncle was Max Gaines, founder and owner of All-American Publications, and then EC Comics, and her cousin was later-EC "New Trend" horror, crime, and science fiction publisher William Gaines.
See Evelyn Gaines's entry on Bails' Who's Who of American Comic Books.