Mariclare Costello stands with her thumbs in her pockets in a scene from the film ‘Let’s Scare Jessica to Death’, 1971. (Photo by Paramount Pictures/Getty Images)
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Mariclare Costello, a prolific actress whose credits include The Waltons and Let’s Scare Jessica to Death, has died.
Costello died on April 17 in Brooklyn, N.Y., her family wrote on Legacy. She was 90.
The actress was born Mariclare Catherine Costello on Feb. 3, 1936, in Peoria, Ill. According to her family, Costello moved to New York after graduate school to pursue a career in theater, where she became a lifelong member of The Actors’ Studio.
Costello’s screen debut came in a small supporting role in Arthur Hiller’s 1967 comedy The Tiger Makes Out, starring Eli Wallach and Anne Jackson.
Mariclare Costello stands on the staircase as she talks with Kevin O’Connor in a scene from the film ‘Let’s Scare Jessica To Death’, 1971. (Photo by Paramount Pictures/Getty Images)
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In 1971, Costello landed the role of Emily, a mysterious drifter believed to be a vampire by a mentally fragile Jessica (Zohra Lampert) in the psychological horror film classic Let’s Scare Jessica to Death.
On television, Costello played the recurring role of schoolteacher Rosemary Hunter on The Waltons, appearing in 15 episodes over five seasons of the classic TV drama from 1972-1977.
In 1977, Costello married fellow actor Alan Arbus, whose roles included Army psychiatrist Maj. Sidney Freedman on the TV classic M*A*S*H. Costello and Arbus remained married until his death in 2013.
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LOS ANGELES, CA – MARCH 29: (L-R) Actor Allan Arbus and wife Mariclare Costello arrive at the opening night performance of “Twelve Angry Men” at the CTG/Ahmanson Theatre, starring Richard Thomas and George Wendt, on March 29, 2007, in Los Angeles, California. (Photo by Ryan Miller/Getty Images)
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Source: https://www.forbes.com/sites/timlammers/2026/04/27/mariclare-costello-teacher-rosemary-on-the-waltons-dies-at-90/
