Kelly broke into features in 1933 as Marion Davies' wisenheimer pal in "Going Hollywood"; she made nearly 40 more films in the next ten years, including "The Girl from Missouri" (1934), "Page Miss Glory" (1935), "Pigskin Parade" (1936), "Pick a Star" (1937), "The Cowboy and the Lady" (1938), "Topper Returns" (1940) and "Danger! Women at Work" (1943).
But the hard-working actress was nearly unemployable by the mid-1940s and found work as a domestic. Some claim it was her drinking, others that her openness about her homosexuality was off-putting in Hollywood. Finally, Tallulah Bankhead (who was hardly shocked by drinking or homosexuality), hired Kelly to support her in "Dear Charles" (1955). Kelly returned to features with "Please Don't Eat the Daisies" (1960) and was one of the coven in Roman Polanski's "Rosemary's Baby" (1968). She had something of a renaissance in 1971, returning to Broadway alongside Ruby Keeler in a revival of "No, No, Nanette", staged by Busby Berkeley (for which she received a Tony Award) and two years later supported Debbie Reynolds in a revival of "Irene".