A woman in her late twenties, Katherine is the most severely affected by the Medusa infection among the survivors. Despite this, she exhibits a maternal instinct towards Tim, the youngest of the group, who is just a little boy. Prior to her infection, Katherine struggled with alcoholism and had a history of abusing her own son, Michael, which led to his placement in foster care. This experience deeply affected her, leaving her with a profound sense of self-loathing and regret. In an attempt to redeem herself, she strives to be the mother to Tim that she never was for Michael.
As the story progresses, the Medusa infection fully overtakes Katherine's body, ultimately turning her to stone.
