Hollywood actress Lauren Chapin, best known for playing the youngest daughter on the 1950s sitcom “Father Knows Best,” died Tuesday at age 80.

“After a long, hard-fought battle over the past five years, the time has come,” Chapin’s son Matthew announced on social media Tuesday. “My mother, Lauren Chapin, pᴀssed away from her battle with cancer tonight. I’m at a complete loss for words right now.”

Chapin, who had a celebrated career as a child actress portraying Kathy “Kitten” Anderson on “Father Knows Best,” was born in Los Angeles on May 23, 1945.

In addition to starring in the beloved sitcom, which aired for six seasons from October 1954 through May 1960, she appeared alongside screen legend Judy Garland in the 1954 film A Star Is Born.

Chapin went on to appear in several television films and stage productions, including the musical comedy “The Amorous Adventures of Don Quixote and Sancho Panza” in 1976.

She later reprised her role in the television reunions “Father Knows Best: Home for Christmas” and and “Father Knows Best: The Father Knows Best Reunion.”

Her older brothers, Billy Chapin ( star of “The Night of the Hunter”) and Michael Chapin (“It’s a Wonderful Life”), were also child actors, according to The Hollywood Reporter.

Chapin later revealed that her real-life childhood was marked by trauma and instability.

She said her mother struggled with alcoholism and that she was molested by her father after being left in his care as a young child. By age 11, she described herself as a “manic depressive personality” and said she had attempted suicide.

“It was very difficult to understand how Kathy Anderson could be loved and protected and Lauren Chapin lived a whole different kind of life,” she said during a 1989 appearance on “Live! With Regis and Kathie Lee.” “I didn’t understand how God could let me suffer.”

She also battled heroin addiction, endured multiple failed marriages and miscarriages, and eventually found sobriety in the 1970s, later becoming a minister and author.