Born 12 January 1969 in Haugesund, Rogaland, Horne is the daughter of automobile mechanic Jon Tormod Horne (born 1942) and his wife Ingebjørg Marie (née Stødle, born 1942), a registered nurse.
Horne attended elementary and high school in Etne, and after graduating lower secondary school, she moved out of her parents' house and into a small student apartment in Sandnes in order to attend upper secondary school [REF].