The newcomer was a girl in the middle twenties, of bold but at the moment rather sullen good looks. She had the bright hazel eyes which seldom go with a meek and contrite heart. Her colouring was vivid, and in the light from the window her hair gleamed with a sheen that was slightly metallic.

Sam the Sudden, chapter 13

This is Dora ("Dolly") Molloy (née Gunn), a young American woman, known to her friends as Fainting Dolly, from her practice of swooning into the arms of rich-looking strangers as a prelude to picking their pockets, hence her alternative nickname of Dolly the Dip.

When she makes her first appearance, in Sam the Sudden, Dolly has been married for just two days to another American petty crook, Soapy Molly. Although Dolly frequently disparages her husband's intelligence, an assessment that is justified by the generally unsuccessful outcome of their criminal escapades, their relationship somehow survives and they reappear together in several stories.

Unlike her husband, Dolly is a firm believer in direct action: in Money in the Bank, Jeff Miller considers her to have the executive abilities of Lady Macbeth.