According to Keno Don Rosa she was born in 1855. Later she married Humperdink Duck and they had three children named Quackmore Duck (Donald Duck's father), Daphne Duck (Gladstone Gander's mother) and Eider Duck. In 1940, however, she was widowed with the death of her husband.
She raised Donald from infanthood and returned him to his parents at some later point. Her grandnephew Gus Goose came to live with her and helps her out sometimes. Grandma Duck also gets help from Gus and Jack, the two mice from Cinderella and usually arranges family gatherings.
In The Life and Times of Scrooge McDuck it is shown that her father is Clinton Coot and her grandfather is Cornelius Coot and her brother is Casey Coot.
She is depicted as driving a Detroit Electric automobile.