Mary Louise Weller, the actress known for her role as Mandy Pepperidge in “Animal House,” died Thursday after a long illness. She was 79.

Her longtime partner Michael Roy Curtis and multiple reports confirmed her death.

Weller was born in New York City on Oct. 2, 1946, and raised in Westwood, Calif. Actor-singer Danny Kaye was her godfather and friend of her father. As a teenager, she trained with the U.S. Equestrian Team.

The actress made her film debut in the 1972 American political comedy “Hail!” In 1978, she starred in the TV film “Hunters of the Reef” and “The Evil” and landed her role as Mandy Pepperidge in the John Landis comedy hit “Animal House.”

When asked in 2012 if she knew “Animal House” would be a hit, Weller said, “I’m pretty sure all of us knew that the movie would be a huge hit… The script was simply brilliant…” She recalled showing then-head of ABC Brandon Stoddard the script: “He also knew it would be an enormous hit… but he warned me that it would be the movie I would always be known for…”

Following her role as the Pi House sorority sister and love interest, Weller appeared in Larry Peerce’s adaptation of Sylvia Plath’s “The Bell Jar,” “Once Upon a Spy,” “Forced Vengeance,” “Blood Tide” and “Q.”

The actress’s television credits include “Baretta,” “Kojak,” “CHiPS” and “Starsky & Hutch.” Her final on-screen appearance was in 1983 on “Quincy, M.E.”

Weller acted in several plays in New York and wrote “Four Alone,” a play that was performed at the Greenhouse Theater in Pasadena, Calif.

Weller is survived by her cousin Sheila Weller, an author whose books include the 2003 memoir “Dancing at Ciro’s: A Family’s Love, Loss, and Scandal on the Sunset Strip” about her family’s life in 1950s Hollywood.