Katie Solent (née Unthank) was the wife of Kit Solent. She died of the blue flu soon after her daughter, Fern, was born. Kit kept a painting of her in the drawing room of his house, which was described as "a woman with long dark hair and an absurd, frilled collar". After she died, her family burnt candles for her on a table beneath the painting so she would "have some light down in the Sunless Country".
Her dead father had been an archaeologist who had worked sometimes with Auric Godshawk. After finding Godshawk's notebook, Kit, after asking some questions, found Katie, who told him about the importance of Fever Crumb and her having Godshawk's memories. She also told of an old tunnel which was supposed to link a house Godshawk built with the Barbican. After spending months looking for it, Katie and Kit didn't find it, but fell in love in the meantime, and, preoccupied, forgot about Godshawk's secrets.
Her favorite scent was a perfume, "Nocturne in Blue, by Eldritch Hooter." Which Kit described as a "sentimental old smell from Scriven times".