Heather Menzies-Urich, best known for her role as Louisa von Trapp in the 1965 classic film, "The Sound of Music," died Sunday night at the age of 68.

Menzies-Urich was the widow of Robert Urich. Her death was confirmed by her son, Ryan Urich.

"She was an actress, a ballerina and loved living her life to the fullest," Ryan said in a statement to Variety. "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 p.m."

Though she had a few minor credits before her role in "The Sound of Music," it was the Academy Award-winning movie that made her a recognizable face. Menzies-Urich was only 15 years old when she appeared as the oldest von Trapp sister. In the '70s, the actress starred in a number of films, including "Piranha" and "Captain America." Her last stint in front of a camera was in the 1990 TV series "American Dreamer," according to IMDB. She may be best remembered for her parting line in "The Sound of Music" – I flit, I float, I freely flee, I fly.

She met her husband while filming a commercial and together they both went on to have successful careers; he starred in a score of films before his death in 2002. After he passed away, Heather dedicated the bulk of her time to the foundation in his name, raising money for cancer research.

The two main stars from “The Sound of Music,” Julie Andrews and Christopher Plummer, are still alive at 82 and 88, respectively. Both continue to act, though Andrews has switched mostly to voice acting, portraying characters in the popular films “Despicable Me” and “Enchanted.”