Mary (1903-1983) was a daughter of Donald Campbell and Mary Matheson, 13 Gravir.

Mary married John Macdonald of 16 Tobson; they had at least three children. The couple moved to West Earshader in 1947 and left in 1964 when they moved to 2 Hacklete, Bernera. Mary and John cared for John's older brother Donald Macdonald, who was physically disabled and unable to live on his own.