[3] In 1940 she married businessman Sverre Fjeld Halvorsen (1910–2005),[1] who was imprisoned at Grini and in Poland during World War II, but survived.

[1] Haslund made her literary debut in 1945 with the short story collection Også vi –.

The independent continuation Det hendte ingenting (1948) was virtually ignored by the press at the time, but has later been regarded as one of her most important books.

[6][7] Hafslund's literary breakthrough was proclaimed with the emerging of Middag hos Molla (1951), and again with her next novel, Krise i august (1954).

[3] She has written several books for children and youth, such as Frøken Askeladd (1953), Barskinger på Brånåsen (1960), and Mor streiker (1981).

[4] A selection of her essays is found in the collections Født til klovn (1977), Kvinner, fins de?

She was inspired by the radical feminism of the 1960s and 1970s, especially by the activity of Norwegian researcher and socialist politician Berit Ås.