She wrote eleven novels, whose protagonist is Sister Mary Helen, an elderly sister who solves crimes. Most of the books are based in San Francisco, California, where O'Marie was born.[2] Sister Carol Anne also ran a shelter for homeless women with Sister Maureen Lyons in Oakland, California.[3]
Sister Carol Anne wrote Like a Swarm of Bees, published by Graphic Visions in 2010. She finished the manuscript shortly before her death. It was written to recall a prophecy and a promise spoken in 1805 by the Abbé Piron of Saint-Étienne, France, by which he foretold that the Sisters of St. Joseph would increase in number and "like a swarm of bees" spread everywhere.[5]