The daughter of high school teachers Karl Clausen and Grethe Clausen, born Jensen, and the youngest of four siblings, Marianne Clausen grew up in a large rented apartment in the 18th-century villa "Stormly" on Godthåbsvej in the Copenhagen neighbourhood of Frederiksberg.
Following her failed first marriage, which was insecure and traumatic, and the death of her father not long after, Marianne Clausen went through some years around 1980 with alcohol abuse.