Nothing is known about Kathy's life prior to or as the outbreak began.
Kathy survived the early stages of the outbreak and eventually found herself as a member of a large group of survivors led by a woman named Natania. Unfortunately, her group would be discovered by a large, hostile organization of survivors led by Simon (who later became Negan's ruthless and sadistic second-in-command) and under his orders, Kathy and her people were forced to gather and provide supplies for them under threat of death. Eventually, under Natania's orders, the group initiated a rebellion to fight back against their oppressors. However, due to being outgunned and outnumbered, their group was defeated. As punishment for their defiance and to deter any further resistance, Simon had his group murder every male survivor above the age of 10 in Kathy's group. It is unknown if any of Kathy's family were among the casualties of the rebellion or subsequent massacre.
Following this and being unwilling to continue working for Simon and his group, Kathy and her group, consisting mainly of females now, fled their community and established a new home at a location called Oceanside and reestablished their community hidden from them. In order to prevent Simon and his group from finding them again, Natania ordered any survivor who happened upon the community to be immediately killed in order to maintain the secrecy of their new home.
When a stranger named Tara is captured after stumbling upon Oceanside, Kathy watches as Beatrice and Natania question her. That night, the women have supper and attempt to persuade Tara to stay with them in Oceanside. However, Tara wants to go back home to her girlfriend and the women offer to escort Tara back to the bridge where she last saw her companion Heath.
After Tara reveals that her group killed a group of bandits at a Satellite station, Kathy and Beatrice are ordered by Natania to kill secretly her. The next morning, Tara discovers their real plan and manages to flee from them. A short time later, Kathy and Beatrice arrive at the bridge and bring Cyndie back home after Tara successfully escapes.
In the following weeks, Tara leads her group to Oceanside to gather guns from the community's armory. When bombs begin to go off in the outskirts of Oceanside, Kathy and Beatrice attempt to run towards the armory but they are stopped by Daryl, who tells them to put their hands behind the head. She obeys him and is brought to the woods with the other Oceanside residents.
When Natania and Cyndie talk about fighting the Saviors, Kathy seems somewhat interested in joining the battle. Shortly after, she is among the survivors to help defend the Oceanside residents from walkers. After the deal is over, Kathy watches as the Alexandrians take their guns.
When Cyndie must decide whether to kill Aaron and Enid or not, Kathy suggests that they kill them on the shore for their actions. However, Cyndie lets them live, but refuses to join the fight against the Saviors, and warns them never to come back to their community.
Upon returning from fishing, Kathy and some Oceansiders watch as an emaciated and weak Aaron kills a walker nearby before collapsing. Having been spotted in the area often by the women, Aaron is ignored except for Beatrice to tell him to find something to drink. Later that day, Kathy and the residents find an exhausted Aaron, begging them to join the fight against the Saviors as they would otherwise continue to be fearful of the outside world.
Just as the Saviors arrive at the Hilltop to slaughter the people inside, Kathy, along with Rachel, Cyndie, and several Oceanside warriors, ambush the bandits with Molotov cocktails, effectively wiping them out and saving the town.
Having moved from Oceanside to the work camp along with several other residents, Kathy is part of the team of laborers working to build a bridge connecting the communities' trade routes. One morning, as Rick travels throughout the camp, Kathy and Beatrice receive weapons from Rosita at the camp's armory. When a group of walkers suddenly ambushed the lumber yard, Kathy is among those to arrive in time to save Daryl, Jed, another Savior, and the injured Aaron.
When the work camp is informed of Justin's death, Kathy watches as the Saviors become furious and start accusing Daryl and Anne of being the culprits. Before a conflict can ensure between the different sides, Rick rides in the middle of the group with his gun drawn and warns everyone to back off.
That night, Kathy is present at her former community and watches on as Arat is set to be executed for her heinous involvement in the murder and execution of the people of Oceanside, especially Cyndie's younger brother.
Kathy smokes and chats with Beatrice in the camp as Rick speaks with Eugene about the bridge project. Later that day, she is horseback and aims her gun at the Saviors when they return to the camp armed with guns and weapons. After gunshots go off, Kathy is knocked off her horse as it runs away from the commotion. She fights alongside her companions and eventually dies in the attack after being shot in the chest by Jed.
Upon returning to the work camp, Rick finds several reanimated residents, including a zombified Kathy. Though weak, Rick manages to shoot her in the head and Kathy's body falls on top of him.
- Killed By
- Jed (Alive, Off-Screen)
During the shootout between the rebelling Saviors and members of the Militia, Kathy is shot in the chest by Jed.
- Rick Grimes (Zombified)
With the last of his strength, Rick manages to shoot a zombified Kathy in the head.
This list shows the victims Kathy has killed:
- Norris (Alive, alongside Carol, Jerry, and Beatrice)
- Numerous unnamed Saviors (Alongside her fellow Oceansiders)
- Numerous counts of zombies and unnamed people
- Kathy is the last named person that Rick Grimes kills during his time on the TV Series, living or otherwise.