Jenna McMahon began her show-business career as one-half of a comedy duo that performed on all of the big talk shows of the 1960s and 1970s, but it was what she and her comedy partner Dick Clair did behind the scenes that made a more lasting impact, as their sketches and screenplays resulted in not one but two hit sitcoms of the 1980s, The Facts of Life and Mama’s Family.

McMahon, who also won three Emmy Awards as a writer for The Carol Burnett Show, died March 2 of heart failure at a hospital in Monterey, Calif., her daughter, Kerry Holden-Dixon, told The Hollywood Reporter. She was 89.

Born on May 14, 1933, and raised in Kansas City, Mo., McMahon moved to New York City where she studied with the legendary acting coach, Stella Adler. As an actress, McMahon’s TV credits would include guest roles on The Twilight Zone, Love, American Style, The Bob Newhart Show and Welcome Back, Kotter.

McMahon met Clair in Los Angeles in 1961, and the duo decided to follow the example of Nichols and May and form their own double-act as Clair & McMahon. By the end of the decade, they were appearing on all of the top talk shows: The Ed Sullivan Show, The Tonight Show Starring Johnny Carson, Merv Griffin, Dean Martin. Here they were on Martin’s show, with their bit about a tap-dancing nun.

In the early 1970s, Clair and McMahon were writing episodes for CBS hits The Mary Tyler Moore Show and The Bob Newhart Show when another CBS Saturday hitmaker poached them. They worked for Carol Burnett for six seasons and won Emmys in three of those years (1974, 1975, 1978). More significantly, they created Burnett’s “Eunice” character for a series of sketches called “The Family” that eventually spun off to become Mama’s Family, starring Vicki Lawrence and running from 1983-1990 on NBC, then into syndication.

Earlier, the duo had written an episode of Diff’rent Strokes — “The Girls School” — that served as a backdoor pilot for another creation, The Facts of Life (1979-1988).

McMahon also wrote episodes of Maude, Flo and Soap, and co-created It’s A Living, the sitcom starring Ann Jillian and Crystal Bernard about waitresses in a rooftop restaurant in Los Angeles that ran from 1980-1989 on ABC and in syndication. With Clair, she also put together a 1987 variety special for ABC that starred Burnett, Carl Reiner, Whoopi Goldberg and Robin Williams. Clair preceded her in death in 1988, causing headlines of his own when he had his body frozen and had his will contested by the company.

McMahon leaves behind a daughter, brother and sister-in-law. Services will be held in California.