Mary Hughes accompanied Billy during his parliamentary sessions in
Melbourne (then the seat of the federal government) and on domestic and overseas trips as Prime Minister (1916, 1918 and 1921). On the 1918 trip, he was in precarious health, and he wanted her to accompany him in order to look after him should he fall ill. Despite his insistence, officialdom did not permit her to travel on the same warship as him, and she went instead in a separate convoy with baby Helen. It was during
World War I that she became interested in the welfare of Australian servicemen, and she visited camps and hospitals in Britain, France and Australia. Both she and her husband became familiar faces at the
Australian Imperial Force headquarters in
Horseferry Road, at the ANZAC buffet at
Victoria station, and in hospitals visiting wounded Australian troops. On her overseas trips she became closely acquainted with influential British women such as
Margaret Lloyd George,
Margot Asquith,
Clementine Churchill and suffragette leader
Christabel Pankhurst. ==Honours==