Diana appeared in the plays "A Christmas Carol" and "Striker." From 1999 to 2000, she played the role of Louisa in the national tour of "Sound of Music" with actor Richard Chamberlain. She also played Anne in "Free Fall" with Sandy Duncan.
Diana also starred in commercials for Thomas' English Muffins, Ford Explorer, Burger King, Snackwell, and Creepy Crawlers. She appeared in a 1998 public service announcement for the ABC network entitled "Dreams."