Actress Sian Barbara Allen, a staple of 1970s television, has died at the age of 78.

The actress, who starred in popular shows such as The Waltons, died of Alzheimer’s disease on Monday in Chapel Hill, NC, according to an online obituary. 

Her sister confirmed her death via a post on Facebook, writing, ‘My wonderful sister, actress Sian Barbara Allen died peacefully today after a long illness. This loss is too hard.’

Allen, was born in Reading, PA on July 12, 1946,  studied her craft at the Pasadena Playhouse beginning in 1964.  

The versatile actress  was a well-known face on television beginning in 1971 with her appearance on Alias Smith and Jones. 

She later had appearances on Gunsmoke, The F.B.I. and the popular Love, American Style. 

Actress Sian Barbara Allen has died at age 78 after a long battle with Alzheimer’s disease 

Her performance as a mentally challenged young woman in 1972’s You’ll Like My Mother earned her a Golden Globe nomination in 1973 for Most Promising New Actress. 

While working on that film, she fell in love with her co-star, Richard Thomas and they were together for several years, according to IMDB.  

She was on two episodes of The Waltons in 1973, playing Jenny Pendleton, a young woman who shared a sweet love story with Thomas’ John-boy in two episodes of the family drama. 

That same year Allen starred with the legendary Bette Davis in the made for TV thriller Scream, Peggy Scream, as a young woman hired to look after Davis, unaware that the previous caretaker has been murdered. 

The brunette beauty was the lead actress opposite Gregory Peck and Jack Warden in the movie Billy Two Hats.

In 1976, she portrayed Anne Morrow Lindbergh in the fact-based TV movie The Lindbergh Kidnapping Case.

She appeared several times on Marcus Welby, MD over the years, as a different character in each episode. 

Allen also had guest appearances in staples such as The Rockford Files with James Garner, on Hawaii 5-0 with Jack Lord and James MacArthur, and made several guest appearances on Ironside with Raymond Burr.

The actress appeared on several episodes of Marcus Welby MD; seen in 1972

In an episode of The Waltons in 1973, Allen starred at Jenny Pendleton, a young woman who shares a romance with Richard Thomas’s John-boy.  The pair men on the set of 1972’s You’ll Like My Mother and were a couple for several years

Allen starred with the legendary Bette Davis in the made for 1973 TV thriller Scream, Peggy Scream, as a young woman hired to look after Davis, unaware that the previous caretaker has been murdered

With so much experience being on crime shows, Allen tried her hand at writing and was hired to create an episode of Baretta, starring Robert Blake, which was sH๏τ in 1978. Allen starred in the episode as well, as Baretta’s cousin Ellen. 

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Allen’s final part was in 1990 on the popular L.A. Law, before trading in her job as an actress for that of wife and mother. 

She married fellow actor Peter Gelblum in 1979 and they shared their daughter Emily, who was named after the lead character Allen played on-stage in a 1976 production of Our Town. The couple divorced in 2001. 

Allen is survived by her daughter, Gelblum, her sisters, Hannah Davie and flash fiction author Meg Pokrᴀss, grandson Arlo Fonseca and nephew Miles Bond.