Her mother, Tilly, was a shorthand typist who later became a schoolteacher. In 1957 she married fellow Scot John McDonald in Glasgow, an RAF sergeant who left the forces to work in technology, first as a quality controller, eventually as a company chief executive. The couple moved out of Halton RAF camp near Wendover in Buckinghamshire and eventually into a £600,000 fivebedroom Georgian-style house on a private estate in Windsor.