Vera-Ellen didn't actually sing any of the songs. Actors Vera-Ellen and Danny Kaye in a scene from the movie 'White Christmas'. USA, 1954. When the character Judy Haynes sings, the parts were all recorded by costar Rosemary Clooney or singer Trudy Stevens. The only time Vera's real singing voice is heard is when they disembark the train in Vermont and the quartet sing the opening lines of "Snow."21 Things You Didn't Know About "White Christmas" - GoodHousekeeping.com
White Christmas: Columbia Inn in Pine Tree, Vermont
White Christmas (Anniversary Edition)--Two former soldiers form a song-and-dance team, join forces with two women singers, and travel to Vermont to put on a Christmas show for the inn owned by their old army general.