Mairi Hedderwick was born in Renfrewshire, Scotland in 1939. She later returned to the mainland to attend the Edinburgh College of Art and then taught for a while. She married and had two children, Mark and Tamara, and in 1962, the family moved to Coll. There, in a house with no electricity, water only available from a well, and a two mile walk to their nearest neighbour, she lived for ten years. The Katie Morag books are loosely based on her life there. The family moved back to the mainland in 1973 to comparative luxury in Fort William, Inverness. By then Mairi had begun illustrating books for other authors, the first published in 1972, soon followed by many others.