Scarlette

Scarlette, known as Isobel in her youth, (COMIC: Political Animals) was the owner of a brothel on Henrietta Street in the 1780s. Scarlette married the Eighth Doctor as part of a ceremony to bind him with the Earth. (PROSE: The Adventuress of Henrietta Street)

Sabbath once referred to Scarlette as the only woman the Doctor ever got close to. (PROSE: Camera Obscura)

Long before meeting Scarlette, the Eighth Doctor had a vision of "a young woman in a scarlet tunic with long blonde hair" while he was exposed to temporal energies on the Supremacy. (PROSE: Father Time)

Early life
She was born in 1762, the year that Mary Culver slit her own throat. (PROSE: The Adventuress of Henrietta Street)

As a young girl in 1774, Isobel assisted Snaddon in caring for George III's royal menagerie. When Mother Francesca of Faction Paradox caught her eavesdropping on a conversation about the War, she helped her to ride the King's woolly mammoth. (COMIC: Political Animals) After Mayakatula escaped her cell, Isobel confronted her in a church, and Mayakatula taught her the ways of the Mayakai, one of the groups who had "inherited" the knowledge of the mysterious elementals following their destruction. (COMIC: Bêtes Noires & Dark Horses, PROSE: The Adventuress of Henrietta Street)

A girl with George's woolly mammoth briefly appeared in a non sequitur clip from Michael Brookhaven's film Mujun: the Ghost Kingdom. The girl is stated to be the daughter of one of the main characters. (PROSE: The Book of the War)

The Babewyn invasion
Scarlette became the owner of a brothel on Henrietta Street. In 1782, she used her Mayakai training to help the Eighth Doctor coordinate a defence against a new danger from outside the conscious universe. She married the Doctor in a ceremony designed to symbolically bind the Doctor to Earth and allow him to participate in its defence; however, over their time together, the two actually fell in love, the ceremony developing a deeper meaning for both parties.

However, recognising that the Doctor's feelings for her would keep him on Earth when he needed to continue helping other worlds, Scarlette faked her death once the crisis was over. (PROSE: The Adventuress of Henrietta Street)

Behind the scenes

 * The Book of the War suggests that Isobel was the daughter of either Awaremi, Lady Wakai, Baron Amatsumara, Kodomo Kami, Kishijoten, or Baron Nichiyobi. Based on the timeline of her birth, it is probable that she was Lucita Marne and therefore a daughter of Faction Paradox as a whole.