She is signed with Geffen Records and as of April 2008, has released 3 studio albums Autobiography, I Am Me, and Bittersweet World.

In 2004 Autobiography was certified 3× Platinum by the RIAA and was one of the best selling albums of that year making Simpson rose to prominence and be nominated on several music awards.

Simpson's first ever nomination was for her work in 7th Heaven, where she played Cecilia Smith, a supporting role.

Also Simpson made the ARIA Decade End Chart selling more than 300,000 singles and ranking in the top 350.

Songwriters are selected each year from the entire BMI catalog, based on the number of performances during the award period.

The winner are based by sales provided by The Recording Industry Association of Japan (RIAJ).

It was established in 1989 that annually honors recording artists based on worldwide sales figures provided by the International Federation of the Phonographic Industry (IFPI).