Gertrude Gadwall

Gertrude Gadwall is a fictional character of the Scrooge McDuck universe created by Don Rosa for The Walt Disney Company. She is only featured in his family tree of Donald Duck's relatives. She is featured as the wife of Clinton Coot, mother of Elvira Coot (also known as Grandma Duck) and Casey Coot, grandmother of Quackmore Duck, Daphne Duck, Eider Duck, Cuthbert Coot and Fanny Coot, great-grandmother of Donald Duck, Della Thelma Duck, Gladstone Gander, Abner Duck, Fethry Duck, Gus Goose and possibly Kildare Coot, and finally great-great-grandmother of Huey, Dewey and Louie and possibly Dugan Duck.