LOS ANGELES (Variety.com) - Actress Heather Menzies-Urich, best known for portraying Louisa von Trapp in the 1965 film The Sound of Music, died Sunday night. She was 68.

Menzies-Urich, the widow of actor Robert Urich, had been recently diagnosed with cancer, according to her son Ryan Urich.

Urich said his mother died on Christmas Eve, surrounded by her children and family members.

She was an actress, a ballerina and loved living her life to the fullest, Urich said. She was not in any pain but, nearly four weeks after her diagnosis of terminal brain cancer, she had enough and took her last breath on this earth at 7:22 pm.

Born in Toronto, Menzies-Urichs first screen credit came in the TV series The Farmers Daughter in 1964. She was 15 when she was cast as one of the seven von Trapp children in The Sound of Music, a box office smash that went on to win five Academy Awards, including Best Picture.

Her other feature films credits included Hawaii, The Computer Wore Tennis Shoes, Piranha, and Endangered Species. Her TV credits included Dragnet, Bonanza, Marcus Welby M.D., The Bob Newhart Show, and starring as Jessica 6 in the TV series Logans Run.

CORRECTION: A previous version of this story mistakenly stated that Menzies-Ulrich played the eldest of the von Trapp children. Her character was the third-eldest.