She was 68 years old.

Heather Menzies-Urich, who played Louisa Von Trapp in The Sound of Music, has died. The Canadian actress, who was best known for her role as the third-oldest Von Trapp child in the hit musical film, passed away over the weekend after a short battle with cancer.

We Mourn the Loss of Heather Menzies-Urich... https://t.co/dpuHJBoBWD pic.twitter.com/V3YqfNSCO3

— The Sound of Music (@SoundofMusic) December 25, 2017

The news of Menzies-Urich’s death was announced by the Rodgers and Hammerstein estate yesterday who said:

“Heather was part of the family. There is really no other way to describe the members of the cast of the movie, The Sound of Music. "And of 'the kids,' Heather was a cheerful and positive member of the group, always hoping for the next gathering. “We are all lucky to have known her, and she will happily live on in that beautiful movie. "We will miss her."

Heather was diagnosed with terminal brain cancer roughly four weeks ago and died on Sunday, according to her son Ryan.

“She was an actress, a ballerina and loved living her life to the fullest. “She was not in any pain but, nearly four weeks after her diagnosis, she had enough and took her last breath on this earth at 7:22pm,” he told TMZ.

Heather was just 15 when she starred in the iconic film in 1965. The news comes a year after Charmian Carr, who played Liesl Von Trapp, died at the age of 73. Some of her fellow Sound of Music co-stars have been sharing their condolences online, including Dan Truhitte, who played Rolf, Nicholas Hammond, who played Friedrich, and Kim Karath, who played Gretl.

I am filled with infinite sadness tonight. My precious friend and SOM sister Heather Menzies passed away this evening. Devastated.

— Kym Karath (@KymKarath) December 25, 2017

A very sad day for all members of the Sound of Music family. @thesom7 @acstudio @DebbieTurner_ @KymKarath . We loved our dear sister Heather very much. pic.twitter.com/R1NaLkET2e

— Nicholas Hammond (@nicholasham1) December 25, 2017

It is such a great sorrow to lose Heather Menzies Urich. She was a joy during filming, such a warm smile, and such a talent and I know she is now with her husband, Robert Eurich. My condolences to the family. Aufwiedersehn for now, Heather. @SoundofMusic @thesom7 pic.twitter.com/S4K6UqGR1i

— Dan Truhitte (@dan_truhitte) December 25, 2017