Romana (Doctor Who)
The White Guardian assigns Romana to help the Doctor during his quest for the Key to Time.  Romana first appears in The Ribos Operation, and was intended as a contrast to her predecessor, the savage Leela.  Romana is initially haughty and somewhat arrogant, looking down on the Doctor (whom she considers to be her academic inferior; she obtained a triple first at the academy, while the Doctor passed with only 51 percent, on his second attempt) and responding to his initial resentment at her presence with icy put-downs. However, she soon gains an appreciation for the Doctor's experience and sense of adventure, and begins to respect him as a teacher.