Mary Louise Kane said Wednesday that von Trapp died the previous day at a hospice in the Baltimore suburb of Towson after suffering congestive heart failure in November.
Von Trapp was the oldest daughter of Austrian naval officer Capt. Georg Ritter von Trapp. His seven children by his first wife were the basis for the singing family in the 1965 film.
Kane lived with Agathe von Trapp for five decades and ran a kindergarten with her at the Sacred Heart Catholic parish in Glyndon, Md.