- "If they shoot first, one of us dies."
- —Dianne to Jesus[src]
Nothing is known about Dianne's life prior to or as the outbreak began, except that she had a sister.
Dianne attends the feral pig hunt with Ezekiel, Morgan, Benjamin, Richard, Alvaro and Jerry. After the pigs are herded into a garage, Dianne shuts the door in order to trap the pigs inside. She is then tasked with retrieving the truck to load up the pigs. After the pigs are loaded up in the truck, she returns to the Kingdom with the others. Later, she is present at the exchange with the Saviors and begins to explain to Morgan who the men are until he interrupts, stating he knows about the Saviors. She raises her weapon after Jared attacks Richard, but the situation is diffused by Ezekiel.
Dianne is at the Saviors exchange with Ezekiel and the rest of his court, waiting for Gavin and his band of men to arrive. A zombie stumbles into the vincinity and Dianne comments that the zombie is wearing the same dress her sister has. She puts it down with an arrow to the head just as the Saviors arrive. After the heated exchange with the Saviors, Dianne comments again on the zombie and the dress before heading back to the Kingdom. She is later present when Ezekiel and other Kingdom soldiers arrive at Carol's house to deliver a casserole.
Dianne is first seen with Ezekiel and the other Kingdom residents as they load a single cantaloupe onto a truck which has been stained with blood.
Dianne is driving the truck when she is forced to stop due to the road being blocked by a row of shopping carts. She searches the area with the others when they come across the empty grave. She helps to clear the carts and they continue on their way.
Dianne raises her gun when Gavin tells them to hand over their weapons. She then watches in horror as Benjamin is shot in the leg by Jared. She helps load him on to the truck and drives to Carol’s house.
Dianne is present for the meeting with the Saviors the next day. She watches helplessly as Morgan strangles Richard to death. She and the others then leave at Morgan’s request.
Dianne appears with Ezekiel as he leads a regiment from the Kingdom toward Alexandria.
Dianne and the rest of the Kingdom residents arrive just as Negan is about to execute Carl and begin to kill the Saviors. She works alongside Ezekiel throughout the battle.
Dianne is then present for Rick, Maggie and Ezekiel's speech to the communities, all united and ready for war.
Diane is among the militia to listen to the leaders' speeches before they launch their assault on the Sanctuary. As the other prepares for the upcoming assault, she calms down Andy's nerves about fighting alongside so many strangers, stating that she will look out after him. After successfully ambushing the Saviors' headquarters, she and the others leave in their vehicles so the incoming horde may swarm the factory.
Dianne is later seen with a small group of soldiers from the militia, which includes Tara, Jesus and Morgan as they stand outside the fence of the satellite station outpost they previously cleared out. It has since been re-settled by Saviors. Morgan asks Dianne if she’ll be able to hit the guards through the fence using her arrows. She expresses doubt.
Dianne is among the Militia to sneak into the Satellite Outpost that has been re-occupied by the Saviors in order to take it over. The group creates a plan to distract the walkers, Morgan creates a gap, distracting the two Saviors and allowing Dianne to silently take out the guards with her bow. She gets into position as the Hilltoppers prepare to assault the unsuspecting Saviors.
Inside, she and Oscar are with a group of Hilltoppers pinned in a hallway as Saviors shoot from a distance. Oscar comments that they've lost touch with one of the groups. He is unable to answer Tara when she asks about Morgan. After a lengthily gunfight, Dianne and her allies are able to gain the upper hand as the Saviors call a retreat. Before Alden, Jared, and the other Saviors can flee, they are captured by Dianne and the rest of the militia.
Dianne is among the Hilltop and Alexandrian forces escorting the around 30 captured and shackled Saviors along a road at by armed guard. On the road, a number of walkers roll down a nearby hill towards the convoy and chaos erupts. Two Saviors are killed, and as the Militia members are preoccupied with the threat, a group of 10 Saviors led by Jared make a break for it, running off into the woods. Morgan gives chase, firing at them as they flee.
Dianne and three other Militia members escort the Saviors back to the road while Jesus tries to reason with Morgan. Dianne later arrives with Tara after Morgan and Jesus fight. He leaves the group while Dianne and the others proceed to return to Hilltop. Dianne and the Hilltoppers then arrive at Hilltop with the captured Saviors.
Dianne is among the Kingdommers and Hilltoppers to watch over the captured Saviors at the Hilltop. She helps move the Saviors inside the walls and into the makeshift prison that was built to hold the prisoners. She then locks them up.
Dianne is in the car with Jesus, Maggie, and Neil on their way to the Kingdom when they are stopped by Simon and the Saviors. Despite Simon's threats to kill Jerry, Simon tells Gary to lower his gun and proceeds to shoot Neil in the head, killing him instantly, much to Dianne's horror.
This list shows the victims Dianne has killed: