Millicent, known as Millie, was the eldest child of marine engineer Jack Dix and Catherine MacLeod of Sunderland. She was born in 1919 on her mother’s native island of Berneray.

The family returned often to Berneray and Millie even spent a few days attending Berneray School in 1931. At the outset of the Second World War, Catherine and the children returned to live on the island, initially at Pol an Oir, her mother's childhood home, and later at 22 Borve. Millie served in the Women's Land Army during the war.

Millie married James Frew of Kinlochleven, where they made their home. Together they were to have two children. Millie lived for a number of years at her mother's old home, the Nissen Cottage at Ferry.