The actresses who played the sisters in "White Christmas" are Rosemary Clooney and Vera-Ellen. Rosemary Clooney was a well-known actress and singer who starred in many movies during the 1950s and 1960s, including "White Christmas" and "The Tender Trap". Vera-Ellen was also a popular actress and dancer who appeared in many musicals, including "On the Town" and "The Red Shoes". Both actresses were known for their grace and elegance on screen, and they brought a sense of beauty and charm to the movie.