Lady Madeline Vaughan was the mother of Sebastian Vaughan. She was a strong believer in the traditions of the Vaughan family and their role in serving Queen and country. To this end, she and her husband expected their son to join MI5 before her husband arranged for him to join Torchwood Three.
Toshiko Sato brought Sebastian's body to Rockfell Hall to be buried with his ancestors, which was important to Madeline. She was somewhat impolite towards Tosh, giving her an idea of why Sebastian was the way he was. She refused to believe that his body had been infected by a cortex leech and attempted to join him before Tosh shot her in the leg, causing him to liquefy as he needed to use her as a battery. Madeline berated Tosh for this. (AUDIO: The Vigil)