A child of vaudevillians, Walker parlayed her wickedly sarcastic deadpan delivery and unconventional looks into a unique comic persona. Perhaps her greatest showcase was "On the Town" (1944), as an aggressively man-chasing taxi driver who tries to persuade a sailor on leave to forego the tourist sites and "Come Up to My Place". Established as a Broadway favorite, Walker next starred as a Marxist coed in the George Abbott-directed musical "Barefoot Boy with Cheek" (1947) and as an heiress-turned-ballerina in the musical "Look Ma, I'm Dancing" (1948). She played Gladys in the acclaimed 1952 revival of "Pal Joey", starred in "Phoenix '55" (1953) and played opposite Phil Silvers in "Do-Re-Mi" (1960), a Comden-Green-Styne musical about jukebox rackets.
On TV, Walker parlayed a high-profile paper towel commercial into a role as Rock Hudson's housekeeper on "McMillan and Wife" (1971-76). She later delighted viewers as Valerie Harper's overbearing Jewish mother, first on "The Mary Tyler Moore Show" and then on the spin-off series "Rhoda" (1974-78). In 1976 she played a wisecracking Hollywood talent agent in her own short-lived series and, when that failed, starred as a wisecracking Las Vegas landlady in "Blansky's Beauties!" (1977).
Walker turned to directing with the Broadway production of James Kirkwood's "UTBU" in 1965 and subsequently became one of TV's busiest women directors, helming episodes of "The Mary Tyler Moore Show", "Rhoda" and "Alice". She made her feature directing debut with the misbegotten Village People disco musical "Can't Stop the Music" (1980) and had returned to sitcoms, playing a mother with a black son-in-law in "True Colors", at the time of her death.