In 1963, Osten graduated from Viggbyholmsskolan, a high school with a curriculum focused on language and creative subjects.

[4] Osten formed one of Sweden’s first fringe theatrical companies, Fickteatern, and began her career as a stage director there in the late 1960s.

In 1975, she formed Unga Klara, a branch of Stockholm City Theater for the purpose of producing theatrical performances for children and youth.

Osten had been cautioned that children this young could not comprehend a drama, but she defied critics, and, during this performance, infants, without previous theater-going knowledge, sat as a theatre audience collectively watching the play for one hour.

The narrative suggests the lived experience of the audience from conception, the time in the womb, birth, meeting with its family, and then on to a life of its own.

Osten found this to be proof of adult significance as performers, as art distributors, and of human love for communication.

She interpreted the reaction of the audience as an innate need in a child for gestures, facial expressions, emotions, language, and bodies from which to learn communication.

[8][9] Osten’s process involved the entire theatrical company; writers, actors, technicians, mask makers, based on research and extended collaboration with audience groups.

Experts outside the theater world, artists, and academic researchers were invited by Osten to contribute with their expertise to the evolutionary and improvisational process of a stage production.

Osten put this method of working to the test in Baby Drama when she wanted to investigate how early an audience can be receptive to theatrical performance.

In 2014, Osten directed a major Nordic theatrical collaboration involving artists from Iceland, Finland, and Sweden.