Malleson appeared in many West End productions, including "The Orphans" at the Lyceum Theatre, and at least one film, "Hindle Wakes". She joined the Hull Repertory Theatre Company for the 1925 season appearing in several productions including "Peter and Paul" and "Advertising April", alongside actor Colin Clive, and a C. K. Munro production of "At Mrs. Beam's". Malleson believed that the short run plays that define repertory theatre were important for the development of young dramatists because they provided an opportunity to see how an audience reacts to one's work. In March 1928, Malleson produced a stage version of her three-act play "The Way" at the Arts Theatre Club in London. The cast, which included Una O'Connor and Charles Carson, was headed by Moyna Macgill in the role of Rosaleen Moore, a part written for her by Malleson. The play, which debuted on 25 March, was performed twice and was reviewed by "The Times" as a "pretentious sham!"