Edith MacDonald, the second daughter of Daniel and Anne MacDonald, was born into a family with a strong connection to the entertainment industry. Her father, Daniel, was a contractor and politician, while her mother, Anne, was a homemaker. Edith's older sister, Elsie, and younger sister, Jeanette MacDonald, both received theatrical training from a young age, and the three sisters went on to perform together in vaudeville houses in Philadelphia.
Edith's early career in show business was marked by her performances in vaudeville, where she toured alongside her sisters and later married Clarence Rock in 1926. The couple spent three years touring the vaudeville circuit before Edith began to pursue a solo career in the 1930s. During this time, she appeared in various stage productions, including "Grand Hotel" and "Dead End," the latter of which caught the attention of an MGM talent agent.
Renamed Marie Blake, Edith signed with MGM and made her film debut in Joan Crawford's "Mannequin" in 1937. She went on to appear in a number of films, including the "Dr. Kildare" series, where she played the role of Sally, a phone operator. After leaving MGM in 1947, Edith changed her stage name to Blossom Rock and began freelancing, taking on a variety of bit parts in films and television.
Throughout her career, Edith appeared in numerous television shows, including the popular series "The Addams Family," where she played the role of Grandmama. Her husband, Clarence Rock, was a night manager at the Beverly Hilton Hotel for 15 years before his death in 1960. After retiring from the entertainment industry, Edith lived at the Motion Picture Country Home, where she spent the remainder of her life.