William McMillan had multiple wives throughout his life, and information about them varies. One wife was Helen Maria O'Reilly, née Gibson, whom he married in Glasgow, Scotland, on 29 August 1892. She was a widow and the granddaughter of Rev. William Boyce. Another wife was Lucie, who continued to reside in Kenya after William's death and died on 4 September 1957 in Nairobi; they had no children. Jane Boag was another wife, whom he married in 1881, and they had five children. Lastly, Eliza Watson married William McMillan in 1861, and they had seven children, with three dying in infancy. Each of these women played significant roles in William McMillan's life and contributed to his personal history. For more detailed information, you can refer to sources such as the Australian Dictionary of Biography 1, Wikipedia 2, and NZ History 3.