Edith MacDonald was the second daughter of Daniel and Anne MacDonald; her father was a contractor and politician. Early on, her older sister Elsie, younger sister Jeanette MacDonald, and she were given theatrical training. Blossom and Jeanette played Philadelphia vaudeville houses while still youngsters.
Marie went to New York where she wed Clarence Rock in 1926; they toured in vaudeville for three years. When vaudeville died, she toured with her husband in "Grand Hotel" and, in 1936, played a streetwalker in "Dead End". The MGM talent agent who saw her in this signed her to the same studio as her now-famous sister Jeanette. Re-named Marie Blake, she debuted in Joan Crawford's Mannequin (1937) and, in 1938, she became established as "Sally" the phone operator in the Dr. Kildare series. After the last of these in 1947, she left MGM, freelancing and doing bit parts. She appeared in television often, becoming widely known through the part of "Grandmama" in La famille Addams (1964) series.
Her husband was night manager at the Beverly Hilton Hotel for fifteen years, dying in 1960. After retiring, she lived at the Motion Picture Country Home.
