Born in New York City, she was the only child of Clyde E. Elliott, a motion picture director known for Frank Buck's "Bring 'Em Back Alive" and "Devil Tiger"; and Marie Flavia Elliott, an actress born in Poland.

As a child, Marietta traveled throughout Asia as her father filmed adventures for Paramount, eventually settling down in Los Angeles and attending Hollywood High school. While there, Marietta excelled as a fencer studying with the great Ralph Faukner at the old Falcon studios. She gave up the blade to study ballet.