She is the daughter of Johan H. Andresen Jr., owner of Ferd AS, who, in 2007, transferred 42.2% ownership stakes each to Katharina and her sister Alexandra. She is the great-granddaughter of Johan H. Andresen, great-great-granddaughter of Johan Henrik Andresen and Anton Klaveness, and great-great-great-granddaughter of Nicolai Andresen. Johan Henrik was the brother of Nicolay August Andresen, and the uncle of Nils August Andresen Butenschøn.