The last time we had three living Queens, was after the death of King George VI. (okay, in this case two Consorts and one Sovereign, but still).
Portrait of Mary, Queen of Scots, which bears a resemblance to Wallis imo
The wedding of Prince Albert, Duke of York (later King George VI), and Lady Elizabeth Bowes-Lyon, 26 April 1923 at Westminster Abbey.
Queen Mary and her mother Princess Mary Adelaide of Cambridge, Duchess of Teck
Queen Mary and King George V in Norway. They attended the coronation of King Haakon VII and (George’s sister) Queen Maud in June 1906.