Strassman died at her Sherman Oaks, California, home on Friday after battling breast cancer for seven years, her sister, Julie Strassman, said Sunday.
"They gave her 2 years to live but she lasted much longer," she said. "She was very courageous."
Strassman had numerous roles on television and in film during her five-decade career.
She played nurse Margie Cutler on the first season of "MASH" before her breakout role in "Welcome Back, Kotter." The show was about a teacher returning to the tough high-school of his youth to teach a classroom full of misfits, including future movie star John Travolta.
She also played Rick Moranis's wife in the Disney hit movie "Honey I Shrunk The Kids" and its sequel, "Honey I Blew Up The Kid."
Born on April 28, 1948 in New York City, Strassman began acting as a teen, replacing Liza Minelli in the off-Broadway musical "Best Foot Forward. She moved to Los Angeles at 18 and landed a steady stream of roles.
She was a member of the Screen Actors Guild national board, and was an active fundraiser for breast cancer research and other social causes, her sister Julie said.
Strassman is also survived by a daughter and a brother.
Plans for funeral services are pending.