Regency Romance where heroine reforms courtesans

[Hannahbanana]

I am looking for a historical romance novel I read 5 years ago. Heroine runs a school that reforms courtesans who want to live respectable lives. The hero might have been a peer looking for his mistress who left him. She gets threatened repeatedly by gentlemen wanting their mistresses back, She also is beautiful but dresses shabby to hide it. I also believe (I don't know if I'm mixing stories or not). That she is the illegitimate daughter of a peer and at one point in the story her 2 half sisters come to visit her.

thanks!

[Lobstergirl, au gratin]

The Reluctant Reformer?

[Nicole]

Shamless by Anne Stuart

[Ann aka Iftcan]

Shameless for Nicole's click.

[Kris]

Hannahbanana, I notice your request is marked Solved. Glad you found your book. What's the title and author?