McWilliams's television appearances spanned every decade from the 1960s through the 2000s. She was a regular player on "Guiding Light" as Janet Mason Norris from 1969 until 1975. She portrayed a prostitute who helped an immigrant stay in the country by marrying him for money on "Barney Miller" in 1977. She was a semi-regular on "Soap" during the second season in 1978. She then appeared on "Benson" (as a different character) when that series premiered in 1979. She remained on "Benson" until 1981: the storyline stated that her character was departing to move away with her husband (her fiancé-turned-husband on the show having been played by Ted Danson).