Lady Rowellanuraven, usually Rowella, was a Coordinator of the Celestial Intervention Agency. She wrote the 943rd edition of The Handbook of Field Operatives. (PROSE: CIA File Extracts)
She was considered its greatest expert on Earth; out of all the Time Lords, her knowledge of its history was considered second only to the Doctor's. As such, she was the one who briefed Rollo on his mission when the CIA caught wind of an alien presence with the potential to disrupt history in 1885 London. (GAME: "The Summons" [+]Part of The Iytean Menace, J. Andrew Keith, The Doctor Who Role Playing Game (FASA, 1985).)
When she received a report from the Sixth Doctor claiming that (contrary to the Doctor's previous report, in his preceding incarnation, that the Tremas Master had died on Sarn) the Master and the First Rani had recently been active in 1830s Killingworth, Rowellanuraven compiled some updated files about the Master and distributed them to all CIA agents. (PROSE: CIA File Extracts)