[3] The daughter of a bookseller Poul Friis and Marie Møller, she was born in Holstebro, and grew up in Skive, graduating from local school Viborg Katedralskole in 1966.
She worked as an au-pair in Paris for a year, becoming interested in geology whilst her brother Henrik was a student in the subject.
The first Cretaceous flower was found by Bruce H. Tiffney in the 1970s in sediment from Martha's Vineyard in the USA, but was seen as an exceptional discovery.
Friis and her collaborators made the technical decision to seek very small pieces of charcoal within likely soft rocks through sieving the crumbled sediment, and then using a microscope to view the resulting fragments.
Through her research network that included Peter Crane and Kaj Pedersen, she collaborated with Annie Skarby to locate and identify many early Cretaceous flowers from southern Sweden.
These appeared to belong to the Chloranthaceae, a group that turned out to be a major part of the flora at that time but is now only represented by a few species.