Madeleine Williams

 was trying to be a poet. She thought the Fifth Doctor was scared because of what was outside. She eventually realised she was part of a war. She wasn't with her unit when they all died. (AUDIO: The Bookshop at the End of the World)

The Doctor would eventually discover that Madeleine, along with many other people throughout history who looked like her, were caused by a group of Time War Daleks who — while on a mission to prevent the rise of Time Lord society on Gallifrey — created a time distortion which created alternate versions of themselves as four un-mutated Kaled people. This time distortion also caused there to be multiple copies of these four Kaleds at various points throughout time and space. (AUDIO: Effect and Cause)