This idea is running through my head for ages, but my writing skills are mediocre at best, and I am not even a native speaker. The story deserves someone better than me.
Daisy, as she calls herself, is a high-rated escort lady in London. And not a dumb one - she started in the business when she was a top student. Now she has a doctorate in history (about economy in Victorian England), but her current occupation pays her way better than anything her degree could offer. One day, one of her clients goes to far, and she dies "on the job".
She wakes up in a dirty, smelly, and loud street as a young girl dressed in rags. Her "friends" are about to desperately (and successfully) get away from "the snatchers", but she does not, due to her lack or orientation in this situation. Some guys grab her, put a sack over her head, and carries her away.
Slowly, she realizes that she is in Victorian London, a teenager at best, and about to be sold to a "gentleman" for entertainment purposes. The guy who "purchased" her, though, does not want her for himself. Instead, she is a "present" for his young adult nephew, who is actually a nice guy, but a bit shy.
She uses her knowledge and skills to win the nephews heart, and helps him getting successful with some useful information about the economy. They fall in love, and the wealth they acquire allows them to cover up her past and introduce her into society as someone suitable to be married.