At some point after 2248, Brin's home planet was devastated by radiation from the Earth probe, Friendship 1. In 2378, the crew of the USS Voyager encountered her, among others, whose bodies had been ravaged by the radiation.
Prior to Voyager's arrival, Brin was pregnant three times - twice with a boy and once with a girl. However, due to the effects of the radiation, all three were stillbirths. Lieutenant Tom Paris, whom the natives were holding hostage, helped deliver her baby, but it too suffered radiation poisoning. Fortunately for her, with the help of The Doctor, the baby was later cured.
When Kathryn Janeway came up with a plan to disperse the radiation on the surface, the leader, Verin, did not believe her and planned to fire antimatter weapons at Voyager. The new mother pulled a weapon and, along with others who had seen that her baby was cured, deposed the leader and accepted Voyager's help. (VOY: "Friendship One")