Upon completing her education, she traveled to Denmark, and taught there for 24 years before returning to Oslo. She made her debut with the novel Raset in 1956. Her books are translated into languages as English, French, Dutch, Spanish, Italian, Swedish and Lithuanian.
Haff was awarded the Norwegian Critics Prize for Literature in 1962 for Bålet (Fire). She received the Dobloug Prize in 1985, the Norwegian Academy Prize in 1988 and the Aschehoug Prize in 1989. She also was awarded the Brage Prize in 1996 for Skammen, the Norwegian Critics Prize for Literature 1996, for Skammen (Shame) and the Riksmål Society Literature Prize in 1996. She has been nominated twice for the Nordic Council"s Literature Prize, once for Den guddommelige tragedie and again for Renhetens pris.
