She became involved in science fiction fandom in her late teens, publishing the fanzine Interim Newsletter for a time.

In 1957 she and her husband founded a production and editorial service for small publishers, Publication Associates; the most notable projects May wrote and edited during this period include two episodes of the Buck Rogers comic strip and a new Catholic catechism for Franciscan Herald Press, a publisher associated with the Order of Friars Minor.

Between 1956 and 1981 she wrote more than 250 books for children and young adults, most non-fiction, under her own name and a variety of pseudonyms; the subjects included science, history, and short biographies of modern-day celebrities such as athletes and musical groups.

[2] Having moved to Oregon in the early 1970s, May began to get reacquainted with the world of fandom; in 1976, she attended Westercon 29 in Los Angeles, her first science-fiction convention in many years.

In August 2015, she was inducted into the First Fandom Hall of Fame in a ceremony at the 73rd World Science Fiction Convention.