Rianna Mayweather was the medic and chief engineer on the ECS Horizon. She lived on Horizon with her husband Mr. Mayweather with whom she had two sons, Travis and Paul, and one daughter. She usually acted as a mediator between the two brothers when they got into disputes.
When Travis returned to the Horizon for a family visit, Rianna had to tell him that his father had died and his brother Paul was the new captain. She redecorated his old room so it would look like it was when he left. She was always worried about Travis, believing that his career in Starfleet was dangerous. Even so, when Travis told her that he might stay on the Horizon, she told him that his destiny was with Starfleet. When Travis and Paul came into conflict, she explained that it would take time for Paul to become a good captain just as it had taken their father. She also convinced Paul to accept the upgrades that Travis installed on the ship. (ENT: "Horizon")