Treschow heads family-owned Treschow-Fritzøe, a group of industrial, commercial & real estate companies. She's considered one of Norway's richest women. Succeeding her father in 1986, she is the 6th generation owning and running the family industry.
The Treschows are a Danish and Norwegian noble family.
In 2004, she married retail magnate Stein Erik Hagen, one of the richest Norwegians. They separated in 2012.