Sian Barbara Allen, a Golden Globe-nominated actress renowned for her roles in television series such as “The Waltons” and “L.A. Law,” died Monday at the age of 78 in Chapel Hill, North Carolina. The cause of death was Alzheimer’s disease.

Throughout the 1970s and 1980s, Allen developed a notable television career, appearing in numerous successful shows including “Gunsmoke,” “Cagney & Lacey,” “The Incredible Hulk,” “Hawaii Five-0,” “Columbo,” and “The Rockford Files.” She also made history as the first woman to write a script for “Baretta” in 1978.

Born on July 12, 1946, in Reading, Pennsylvania, Allen was brought up by her mother and grandmother. After high school, she secured a scholarship to the Pasadena Playhouse, which initiated her acting journey. She was part of the Journeyman program at the Mark Taper Forum under the guidance of acting teacher Peggy Feury, eventually becoming one of the last contract players at Universal Studios.

Allen gained recognition with her role in the 1972 film “You’ll Like My Mother,” acting alongside Patty Duke, Rosemary Murphy, and Richard Thomas. Her performance led to a Golden Globe nomination for most promising new actress in 1973. During the production, she began a relationship with co-star Richard Thomas, known for “The Waltons.” She later appeared in two episodes of the series in 1973, portraying Jenny Pendleton, John-Boy’s love interest.

After “You’ll Like My Mother,” Allen co-starred with Bette Davis in “Scream, Pretty Peggy” and appeared in the Western “Billy Two Hats” with Gregory Peck and Jack Warden. She also took part in “The Lindbergh Kidnapping Case,” featuring Anthony Hopkins.

“Sian was most often cast in roles in which her characters showed great vulnerability and uncommon empathy, which won her a legion of fans all over the world,” her obituary reads. Her theater work was significant, with her role as Emily Webb in “Our Town” at the Williamstown Theater Festival in 1976 being a particular favorite. She named her daughter Emily after this character.

Receiving the Key to the City of Reading was a source of pride for Allen. After her last on-screen role in “L.A. Law” in 1990, she left Hollywood to focus on politics and family. Along with her then-husband, Peter Gelblum, and their daughter, she volunteered in Jackie Goldberg’s 1993 Los Angeles city council campaign. Her family noted she was a “staunch supporter of Cesar Chavez and the United Farm Workers and never crossed a picket line in her entire life.”

In addition to acting and activism, Allen was recognized as a “remarkable poet” with “boxes of writing” to her name. Her daughter described her mother as passionate about literature, music, and comfort foods.

Allen is survived by her daughter Emily Fonseca, two sisters, a nephew, her ex-husband Peter Gelblum, several cousins, and her grandson Arlo Fonseca, “who made her laugh more than anyone could dream.” Donations in her memory are encouraged to go to the AuthoraCare Collective Hospice of Burlington or local organizations fighting oppression.

Allen’s legacy includes her television and film work from the 1970s and 1980s, leaving a lasting impact on American entertainment. Her role in “The Waltons” continues to be celebrated by its dedicated fanbase.

Her contributions to television history encompass her performances and her pioneering role as a female television writer, breaking barriers in a predominantly male industry. Her script for “Baretta” marked a significant advancement for women in television production during the 1970s.

Her death signifies the conclusion of a life devoted to artistic expression and social causes, leaving behind a diverse body of work spanning decades of American television and film.