Isobel Watkins
Isobel Watkins was a photographer and the niece of Professor Watkins. She assisted the Second Doctor and his companions Jamie McCrimmon and Zoe Heriot against the Cybermen.
History
Isobel was invited to take a photoshoot of International Electromatics' director Tobias Vaughn. She appreciated the chance to extend her photographic experience and make some money, but saw that the entire job was just an excuse to try to get her to entice her uncle Watkins to work for IE. (PROSE: Prelude Iceberg)
Isobel was staying at the home of Professor Edward Travers in London when she met the Doctor, Jamie and Zoe. She assisted in the defeat of Tobias Vaughn and the Cybermen. In doing so, she met Jimmy Turner of UNIT, (TV: The Invasion) whom she later married. (PROSE: The Scales of Injustice)
When Isobel went public with her story, C19 began harassing her, telling her to keep quiet. Her claims that Earth had been invaded by aliens were not believed and her photographs of the Cybermen were dismissed as fakes. She became a standing joke on Fleet Street and her boyfriend left her as his career was threatened. Months later, she was interviewed by the reporter James Stevens, who was investigating UNIT. It was from Isobel that he first learned of the existence of the Doctor. (PROSE: Who Killed Kennedy) Ruby Duvall also interviewed her about the subject. (PROSE: Iceberg)
Personality
Isobel was a feminist, and got very angry when she was told photographing the Cybermen was "no job for a woman" by Brigadier Lethbridge-Stewart. She got on very well with Zoe Heriot, who modelled for her. (TV: The Invasion)
Behind the scenes
Isobel Watkins' subsequent life as shown in Who Killed Kennedy can be viewed as a slight retcon, as The Invasion ended with her getting a lucrative job because of her photos of the Cybermen invasion.