In 1909, the Duchess founded the Derbyshire branch of the Red Cross and became its first president. She was appointed Mistress of the Robes to the newly crowned Queen Mary in 1910. In 1916, the Duke accepted the appointment of Governor General of Canada, and his wife relinquished her position to accompany him, along with six of their children. While in Canada, their daughter Lady Dorothy met Harold Macmillan, the future prime minister. While the Duke was delighted with the match, the Duchess was unhappy that Macmillan, though wealthy, was the member of a mere tradesmen family. She favoured a match between her daughter and the heir to the Duke of Buccleuch instead. Nevertheless, Dorothy and Macmillan were married in April 1920.