Even in a stand your ground state she'd 99% get charged. She drove away. Stopped and opened the door. She could have easily kept going. That's not self defense.
Ifs ands & buts: When he opened the door and started assaulting her. That's the self defense time period if she shoots him. But she started the car and drove away And then stopped to continue the confrontation with the intent to shoot him.
My viewpoint is she retreated and he chose to re-engage. Strategic error.