Born into the Scottish nobility in the first year of the twentieth century, Lady Elizabeth Angela Marguerite Bowes-Lyon became the Queen Consort on the accession of her husband Prince Albert to the throne (as King George VI) in 1936. When she became a window in 1952 and her daughter became Queen Elizabeth II, she was formally known as the Queen Mother but more informally and affectionately by the general public as the "Queen Mum". Her children Elizabeth and Margaret, though grown, continued to call her "Mummy".
Bernard, Thomas L.
"Mothers and Their Vowels,"
Word Ways: Vol. 36
, Article 19.
Available at: http://digitalcommons.butler.edu/wordways/vol36/iss1/19