Celeste Rivers

Professor Celeste Rivers was a senior scientist working at the Pharos Institute. She showed Sarah Jane Smith around the Institute, much to the dismay of Korst Gogg Thek Lutiven-Day Slitheen, then masquerading as the Human child prodigy Nathan Goss. (SJA: The Lost Boy) She later unofficially permitted Sarah Jane to take away a fragment of the Weserbergland Meteorite kept at the Institute. (SJA: The Day of the Clown)

Behind the Scenes
She will appear in series 3 and it will be bigger than her first two appearances. Though confirmed by the production, team, her name has not gotten mentioned so far on-screen.