Cox is probably best known for appearing as Jan Brady in several recent incarnations of The Brady Bunch such as The Brady Bunch Movie, A Very Brady Sequel, and the Off-Broadway play The Real Live Brady Bunch, and reprised her performance in episodes of Moesha and Wings.
Outside of Jan Brady, Cox was in the TBS comedy 10 Items or Less as Amy Anderson. She also appeared in an episode of The New Adventures of Old Christine with Hamish Linklater. She can be seen as a woman auditioning for the role of Samantha in the 2005 film version of Bewitched with Kristin Chenoweth. She also played Tiffany Riley Clark in the show Lovespring International.