Doctor Bettina Fairchild was an entity created by the Scarrans in order to mentally torture John Crichton through a simulation of Earth. While, physically, she was an exact replica of Aeryn Sun, her personality was vastly different -- she was something a party girl, and joked much of the time, even with her patients.
In the simulation, Fairchild was one of the doctors who worked with John after the failure of the Farscape Project. She also spent time at a bar, immediately befriending Gary Regal. As the simulation became increasingly bizarre, her rational attitude became increasingly mocking and her outfits became more and more absurd.
Dr. Bettina Fairchild appeared in one episode of Farscape.