Rodan was a female Time Lord who worked as a controller on Gallifrey, maintaining the protective transduction barrier around her homeworld and monitoring spacecraft in the vicinity of her homeworld.
Profile
She befriended Leela. Both women were exiled outside the Capitol by the Doctor as part of the latter's ploy at pretending to collaborate with the Vardans. She found such a natural environment hard to cope with mentally. After the Doctor had made the transduction barrier and first the Vardans and their masters the Sontarans invaded Gallifrey, she worked to restore it. (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.