Rodan was a female Time Lord who worked as a controller on Gallifrey. She befriended Leela and worked with her in order to help the Doctor defeat a Sontaran invasion of Gallifrey. (DW: The Invasion of Time)
Behind the scenes
Other than Susan Foreman, Rodan was the first female Gallifreyan seen on screen. A Time Lady, Romana would join the the Doctor in his travels in the following season of the series.