Agathe von Trapp, eldest daughter of the Austrian family who inspired The Sound of Music, has died at the age of 97 in the US state of Maryland.
She died in a hospice in the Baltimore suburb of Towson after suffering congestive heart failure in November, a long-time friend told reporters.
In the hit musical she was portrayed as Liesl, singing the duet Sixteen Going on Seventeen with Rolf.
While liking the film version, she felt her father came over as too strict.
"She cried when she first saw it because of the way they portrayed him," said Mary Louise Kane, the friend who lived with Agathe von Trapp for half a century.
"She said that if it had been about another family she would have loved it."
The 1959 Rodgers-Hammerstein musical, made into a film in 1965 with Julie Andrews and Christopher Plummer, tells the story of a singing family who flee the Nazis across the Austrian Alps.
The original Trapp Family Singers performed in Europe and North America in the 1930s-40s with their father, Austrian naval Capt Georg Ritter von Trapp, and stepmother Maria.
Four of the Singers are still alive: Maria von Trapp, 96; Rosmarie von Trapp, 81; Eleonore "Lorli" von Trapp Campbell, 79; and Johannes, 71.
Johannes said his sister had been a private person who was also a talented sketch artist, the Associated Press news agency reported.
She will be buried in the spring at a cemetery at the Trapp Family Lodge in Stowe, Vermont, he added.