Kate Brewster

Katherine "Kate" Connor (née Brewster) is the wife of Resistance leader, John Connor and is second in command of the Resistance during The War Against the Machines in the T3 & T4(Salvation) timelines.

Post Judgment Day (Terminator 3: Rise of the Machines)
By 2032, her husband was killed by a T-850. Kate did, however, manage to reprogram the machine to travel back in time to July 25, 2004 to save John.

Early life
Kate grew up before the war, living in ignorance until she met John Connor. The pair attended school together, and are implied to have had a romantic encounter in their younger days.[1]

Kate is the only daughter of Lieutenant General Robert Brewster, the military director of CRS Autonomous Weapons Division. Kate's mother divorced her husband and left them when she was still at veterinary school. After finishing school, Kate went on to become a veterinarian, working at the Emery Animal Hospital, and became engaged to fiancé Scott Mason.

Assassination attempt
In 2004, her normal life was to change. Upon reacting to an animal emergency at the Emery Animal Hospital, Kate met John Connor, with whom she had previously attended school, and with whom she had experienced her very first kiss. With John Connor and a reprogrammed 850 Series Terminator, Kate managed to escape a T-X which had been sent back in time to eliminate her. Practically kidnapped by both John and the T-850, Kate learned the truth of things to come: of Skynet, and of Judgment Day. Setting off with the others to CRS to try to stop her father from activating Skynet, Kate was unsuccessful, and her father was killed by the T-X.

Judgment Day
Getting to the Crystal Peak Control and Command Center, a hardened fallout shelter facility in the Sierra Nevada Mountains for VIPs, Kate and John were able to survive Judgment Day as the nuclear missiles fell. Using the communications equipment within the facility, Kate helped John to get in touch with survivors and co-ordinate a Resistance force.

Terminator Salvation timeline
During the war, Kate married John and became Kate Connor. She was one of the two medics in John Connor's unit prior to his promotion to be one of the Resistance leaders. She constantly begged John to allow her to be a field medic. She already knew that the men and women under her husband's command respected her as a leader as well, but she felt that she had to prove that she could also lead in battle. He still refused, prompting Kate to defy his orders to stay at the base. She instead tagged along with Barnes' squad during a battle to capture one of Skynet's facilities, the battle that would lead to John's promotion. However, shortly before the battle took place, Kate realized that she was pregnant with John's child.

Kate was a high-ranking member of the staff of John's Resistance Base in 2018 and served as one of the Base's Doctors. Following his accident, Marcus Wright was brought to her and she attempted to mend his injuries — learning that he was a Terminator in the process. She conducted an examination of the machine and reported to Blair Williams that John had decided to dismantle Wright rather than let him live. She also tried to reassure John that his father, Kyle Reese, would be fine despite being a target of the machines.

When John decided to launch a rescue mission, she initially tried to talk him out of it, but eventually relented. After the destruction of Resistance Headquarters by Skynet, Kate ordered the mission to Skynet Central to rescue John. When John is brought back by Marcus and Barnes, he is mortally wounded. Kate ordered Blair to land the helicopter on a safe spot and ask the surgeon team to stand by. Later, she gives John a heart transplant surgery with the help of Marcus, who give his heart to save John's life.

Trivia

 * Kate Brewster will meet Thomas, Twilight, Brian, & their friends in Thomas and Twilight Sparkle's Adventures of The Terminator III: Rise of the Machines and then see them again in Brian Griffin's Adventures of The Terminator: Salvation.