[1] Greenwood was born Marianne Hederström in Gällivare,[1] and raised in Kiruna and Skellefteå, all in northern Sweden.

Before the end of World War II Greenwood moved to Stockholm and studied at the art school of design.

For several decades she lived with indigenous people in the Americas, the Pacific Islands, in Papua New Guinea and parts of Asia.

In 2005 Greenwood received a Women of Discovery Award for Lifetime Achievement from Wings Worldquest[3] in New York.

A documentary film about Greenwood entitled "Catch the Moment" premiered in 2008, and has been broadcast on public service television in Denmark, Iceland, Norway and Sweden.