Mrs. Beakley was Uncle Scrooge's maid, who was permitted to live in McDuck Mansion with her granddaughter Webbigail Vanderquack. (A granddaughter who Uncle Scrooge treated like a niece.)
Not well known is Mrs. Beakley's first name- Bettina. By the end of the show's run, Mrs. Beakley is like a member of the family.
