Princess Märtha Louise is a certified physiotherapist, following education in Oslo and internship in Maastricht, Netherlands. She has not practised her profession, however, choosing instead, from her fascination in traditional Norwegian folk tales as well as a love of music, to establish her own commercial entertainment business based on giving public and televised performances reciting folk tales and singing with well-known Norwegian choirs. In December 2003, she took part in Oslo Gospel Choir's Christmas concert with a solo performance, included on the companion CD album.

On May 24, 2002 she married author Ari Behn (born 1972 as Ari Bjørshol; he later took his grandmother's name).

On April 29, 2003 she gave birth to a daughter, Maud Angelica Behn.