Fahn is a member of the ensemble in the original Broadway cast of Stephen Schwartz's musical Wicked. In March 2004, Fahn played an understudy for Glinda, replacing Melissa Bell Chait who suffered a stroke. Fahn departed the show on October 31, 2004. She later became an original cast member of the Los Angeles sit-down productions, performing in the ensemble and again understudying the role of Glinda before departing on December 30, 2007.