She was one of the first four women to stand for the Parliament of Australia, running unsuccessful as an independent Senate candidate in New South Wales at the 1903 federal election.

She and her sister visited the Sydney International Exhibition in 1879, but when their money ran out they were forced to work as domestic servants.

In 1880 the family settled at Marrickville and Mary became a nursemaid to the children of Colonel Charles Roberts.

She married postal clerk Henry Hill Ling on 3 September 1889 at the Salvation Army barracks in Burwood; they separated in 1897 and divorced in 1906.

A Psychological Interpretation of the Gospel (January 1917) received a US publication in Boston and Moore-Bentley sailed to America later that year; she was repatriated at government expense in 1918 and blamed her disappointing time in America on the "Secret Service" and the Australian government's misrepresentation of her anti-conscription activities.