Melba
From Tardis Wiki, the free Doctor Who reference
Melba, also known as Mel, was Carla Langer's sister and Clyde Langer's aunt.
Clyde's father, Paul Langer, ran off with her to Germany. When she became pregnant in 2009, Paul returned to London and told Clyde. He later returned to her after Clyde convinced him to. (TV: The Mark of the Berserker)
Notes
In the script for Mark of the Berserker: Part Two: Page 24: Carla refers to her maiden name as Banks, implying that Melba's surname is the same.[1]
