Louise Nathalie Sørensen was born in Copenhagen, took her middle school exam in 1941, worked as a maid, writer, and journalist, and made her debut with poems in Vild Hvede in 1943.
Her first poetry collection, with the characteristic post-war title Rodløs, appeared in 1946. In 1947 she married the writer Erik Knudsen, and the same year she participated in the Nordic-Soviet writers' conference in Helsinki. Like Sonja Hauberg, she contracted typhoid, but survived.
Her multifaceted oeuvre is characterised by her eminent linguistic and critical talent. Both in the verse and imagery of her earlier poetry collection and in her more experimental collections such as Epistler, 1966, the reader notices a surplus linguistic energy. With publications such as her essay collections Digternes damer, 1964, and Mands- og moderhjerte, 1969, she started a revolt against literary gender roles and the idealisation of motherhood, which the modern women's movement continued.
In the 1970s, she created her own opinion genre. She used it in her documentary book Den nødvendige nedtur, 1977, in which she portrays the first author of emancipation, Mathilde Fibiger, and the controversy surrounding her book Clara Raphael. An important later publication is her essay Søsterparten. Et essay med variationer, 1987, which deals with aspects of gender philosophy and the gender role debate from John Stuart Mill up to the modern women's movement. The hallmark of all of her works is a characteristic combination of linguistic and critical energy and unfailing commitment.