Louise (Daleks' Invasion Earth 2150 A.D.)

Louise was the niece of Dr. Who and the cousin of Susan and Barbara.

Biography
After Barbara and her boyfriend Ian Chesterton had seemingly left Tardis, she joined her uncle and Susan where they once again encountered the Daleks as well as the telepathic native Martians. After Louise was captured by the Daleks, Dr. Who learned that the Martian Sphinx was in fact an ancient weapon whose secret had been forgotten. He was able to reactivate the Sphinx and used it to destroy the invading Dalek forces, only moments after he had rescued Louise from the Dalek Flying Saucer. (DWMS: Daleks Versus the Martians)

The three of them and a police constable named Tom Campbell subsequently travelled to London in 2150 and found that it had been devastated by a Dalek invasion years earlier. Once there, she assisted in freeing Earth from Dalek occupation. (Daleks' Invasion Earth 2150 A.D.)

Personality
Louise was a caring and inquisitive person. When Susan was hurt, Louise looked after her. She was also willing to help strangers when hurt or in trouble.

Behind the scenes

 * Louise is the only lead female companion created specifically for the movies, though her equivalent in TV: The Dalek Invasion of Earth would be Barbara Wright.
 * The character was added to the film as a replacement for the movie version of Barbara when Jennie Linden did not return for the second film. This allowed the romantic subplot originally assigned to the older version of Susan in the TV story to proceed.