Kim Brown is the loyal wife of the now Sergeant First Class Bob Brown. In the first season, she and Bob, then a Staff Sergeant, are new arrivals to the Unit. At first, she is confused by the new rules of the wives of Unit team members, but soon Jonas Blaine's wife, Molly, takes Kim under her wing and shows her the ropes.
In the first season, Kim becomes pregnant with her second child; she and Bob also have a daughter named Serena. In order to help to provide for their growing family, and to keep herself occupied, she takes a job at a local radio station known as KTML "The Missile". Between the 1st and 2nd seasons of the show their son, Theodore "Teddy" Roosevelt Brown, is born.
Between season 3 and 4 Kim's 2nd daughter, Emily, is born. In Episode 4.22 Bob has first met Emily in person.