Took up the game at the age of six and, by the age of 15, was proficient enough to win the first of five Norwegian Amateur titles. Also won the British Girls Championship in 1999 and twice represented Norway in the world amateur team championship for women, the Espirito Santo Trophy. Also represented Europe in the 1997 and 1999 Junior Ryder Cup Matches. Turned pro in September 2000 at age 19 and gained her Ladies European Tour card at the 2001 LET Qualifying School. Played in ten events in first season without missing a cut and, on second start, won the Open de France Dames. Finished second on the Order of Merit and was named LET Rookie of the Year. Won first major – the LPGA Championship – in 2007, a season in which she won five times on the LPGA Tour and once on the LET. Added a second major, the Evian Masters, in 2013.