Various details of the von Trapp story were altered for the play and the film.
The Captain's eldest child was a boy, not a girl, and the names of the children were changed (at least partly to avoid confusion, as the Captain's second-eldest daughter was also called Maria).
The repertoire of the Trapp Family Singers was entirely classical, with a special focus on early motets.
The von Trapps spent some years in Austria after Maria and the Captain had married (in 1927) � they did not have to flee right away � and when they did it was to Italy, not Switzerland, via train, not foot.