The daughter of a miner, William Smith, Mary married Frans Mayger (also spelt Meaker) at Burra, South Australia. In 1885 the Maygers were employed by George McCulloch at his Mt Gipps homestead near Broken Hill, with Mary as housekeeper. Frans died in May that year after falling from his horse, and Mary moved to Melbourne. There she met with George McCulloch once again and returned to Broken Hill as his fiancee. The pair were married in the Strand Registrar's Office in London on 11 May 1893, and travelled for two years in Britain, Egypt and Canada. They had one son, Alexander.

George McCulloch died in London in December 1907, leaving his £436,000 estate to his wife along with a collection of art that was subsequently auctioned for a total of £136,859. In 1909, Mary married Scottish artist James Coutts Michie. He too died in London, in 1919.

During the First World War, Mary presided over a Red Cross Hospital and was decorated with the Order of the British Empire for her services.

Mary Coutts Michie visited Broken Hill once again in 1925. Adding to donations by George McCulloch, she gave a series of paintings to the Broken Hill City Gallery.

Sources used to compile this entry: Camilleri, Jenny, Some Outstanding Women of Broken Hill and District, Jenny Camilleri (Broken Hill Historical Society/Broken Hill Council), Broken Hill, NSW, 2002.