Canadian actress Heather Menzies-Urich, best known for her roles as Louisa von Trapp in the 1965 Oscar-winning film The Sound of Music and Jessica in the TV series Logan’s Run, has died.

The widow of Robert Urich, Menzies-Urich died Sunday night . She recently had been diagnosed with cancer, her son Ryan Urich told Deadline’s sister pub Variety. She was 68.

The Toronto-born Menzies-Urich had her first screen credit in the 1964 TV series The Farmer’s Daughter, but it was her role a year later as Louisa, one of the von Trapp children in The Sound Of Music, for which she is best remembered. Louisa’s the prankster, always trying to put one over on Maria, the governess played by Julie Andrews. The film won  five Oscars, including Best Picture.

From The Sound of Music, Menzies-Urich went on to appear in features including Hawaii, Piranha, The Computer Wore Tennis Shoes and Endangered Species. On the TV side, she was known for her starring role as Logan’s female companion Jessica in the Logan’s Run television series. Her other TV credits include Dragnet, Bonanza, Marcus Welby M.D., The Bob Newhart Show, Vega$, The Love Boat, Spenser for Hire and T.J. Hooker, among others.

Menzies-Urich created the Robert Urich Foundation in honor of her late husband, who died in 2002 of a rare form of cancer. She spent most of her time in recent years devoted to the non-profit organization that raises money for cancer research and patient care.