Karen is one of The Governor's enforcers tasked with protecting Woodbury's wall. She is seen trying to leave Woodbury when conditions worsen, and she becomes angry when Noah is forced to join Woodbury's army. She is among The Governor's soldiers who attack and fail to take over the prison. When the army rebels against returning to the prison, The Governor shoots all of them, except his top henchmen (Martinez and Shumpert), and Karen, who hides under a body and survives. She is found hiding in a truck by Rick, Michonne, and Daryl, and is among the Woodbury citizens who are taken to the prison.

By the time Season 4 begins, she has started a relationship with Tyreese. When an influenza outbreak spreads throughout the prison, Karen begins to get sick and is quarantined until she gets better. However, Carol kills Karen and burns her body in an attempt to keep the virus from spreading.