The Theatre Information Bulletin was a sort of industry newsletter, according to the New York Sun. It was mimeographed weekly and was filled with "facts and figures about openings, closings, casts, credits, and attendance in the New York theatre world." Its rival publications included the extant Theatrical Index, which is published by Price Berkeley. She and partner Betty Blake launched their career at the Theatre Information Bulletin in 1944, taking it over from New York Times drama reporter Sam Zolotow. The publication continued until the early '90s, when it became the Performing Arts Insider, published by Richmond Shepard. Following in the footsteps of her mother, a silent film actress, Ms. Marlowe began her career in the theatre as an actress, dropping out of Cornell at 19 and appearing on Broadway in a small role in Mr. and Mrs. North. That same year, she married New York Sun critic and columnist Ward Morehouse, a chubby, courtly Southerner with a eye for actresses. The two shared an ebullient lifestyle that included frequent visits to Sardi's and the "21" Club. They remained married until 1948.

In 1951, the Ithica-born Joan Marlow published the book "The Keys to Broadway," an instructional guide for actors based on her own struggles in the business. Ms. Marlowe and Blake also published New York Theater Critics' Reviews, a reference work that was sold to Playbill in the early 1990s, and Ms. Marlowe served as the president of the Outer Critics' Circle and New Drama Forum.

She married Roderic Warren Rahe, a chemist, in 1952. He survives her, as do her sons sons Roderic Warren Rahe, Jr., and Ward Morehouse III, a theatre journalist.