Christensen was born in 1972 in Norway. She concluded her vocal training in 1997 at the state conservatory in Oslo. In November 1998 she made her extremely successful debut at the Norwegian National Opera as the Queen of the Night and was distinguished with the prestigious Esso award for outstanding opera performances. Since December 1999 she has been engaged by the Innsbruck Theatre where she has sung the main role in Händel's Partenope, Liu in Turandot and the Queen of the Night. In June 2000, she received a grant for her part in Partenope and was awarded the Eberhard Wächter medal.