Born on 9 July 1944 on the Danish island of Als, she was the daughter of the medical doctors Harald Eyvind Roesdahl and Anna Helene Refslund Thomsen. The second youngest of four children, she grew up in an old farmhouse in Tandslet where her parents had their practices. As a child, she was strongly influenced by her maternal grandmother, the author and politician Ingeborg Refslund Thomsen, spending much of her time at Brundlund Manor, her grandparent's home in Åbenrå. A creative child, she dreamt of becoming a journalist, writing short stories and poems. After matriculating from highschool in Sønderborg, she spent half a year as an au pair in Cambridge, England, improving her command of English. On her return to Denmark, she studied German and English at the University of Copenhagen. Participating in political student life, she met Karen Syberg with whom she set up Rødstrumperne, a small group based on the Americanfeminist movementRedstockings, which soon developed into the Danish Redstocking Movement. A demonstration in central Copenhagen in 1970 ended with the women discarding their bras with a banner declaring Hold Danmark ren. Further activities in support of women followed, including the creation of a "Women's Camp" on the island of Femø and a call for abortion rights in 1970. Vasbo abandoned her university studies in 1973, becoming a medical assistant in Bispebjerg Hospital. Many of the members of the Redstocking Movement were either already lesbians or decided to adopt lesbian ways. Vasbo, who had undergone a short period of marriage, was among them. In the face of opposition to lesbianism by many of the Redstocking members, the Lesbian Movement was established in 1974, soon enjoying a membership of 200 activists. Together with the Norwegian activist, Gerd Brantenberg, who had become her partner, Vasbo moved to Oslo where she worked as a crane driver. On the basis of diary notes, she wrote Al den løgn on kvinders svaghed, published in Danish and Norwegian in 1976 and later in German, describing how a woman could take up a job traditionally reserved for men. It was the first Danish book which openly described a woman's experiences from a lesbian viewpoint. Vasbo broke off her contacts with the Lesbian Movement in 1981 when she met a Danish priest, Leo Thomsen, in Italy. She developed a difficult relationship with him which ended in a separation a month before his death in 1998. Their romance was described in Miraklet i Amalfi, bringing Vasbo renewed attention. She went on to write a historic novel set in 7th-century England, Hildas sang, combining family life and sex. It was warmly welcome by the critics.
Selected works
1976: Al den løgn om kvinders svaghed
1980: Efterårsferie ved fjorden, short stories
1980: Måske har jeg haft en anelse, poetry
1981: Sygehjælper i æbletræernes blomstringstid, short stories
1982: Den enøjede killing, short stories
1984: Miraklet i Amalfi, novel
1985: Anna-Amanda, short stories
1990: Det er det, jeg siger: Man vil begå mord!, short stories
1991: Hildas sang, historisk roman fra 600´årenes England, novel
1993: Glæden ved at kigge ud ad vinduet, essay
2004: Artemis, beretningen om en kat
2008: Der mangler en sang om solsorten, novel
2018: The Song of Hild, English translation of Hildas sang