Once Upon a Maiden Lane by Elizabeth Hoyt

Miss Mary Whitsun is far too intelligent to fall for the rakish charms of a handsome aristocrat. But when the gentleman in question approaches her in a bookshop, mistaking her for his fiancée, Lady Johanna Albright, the flirtatious encounter only raises more questions. Could Mary, a servant raised in a St Giles orphanage, actually be Lady Joanna’s long-lost twin sister? If so, Mary has been betrothed since birth—to the rakishly handsome artistocrat himself.

Henry Collins, Viscount Blackwell, is far too intrigued by Mary to let her go so easily. He’s drawn to her sharp mind, indomitable spirit, and the fiery way in which she dismisses him—ladies simply don’t dismiss Lord Blackwell. But as Mary makes her first hesitant steps into society, she can’t help but wonder if she truly has a place in Henry’s world—or in his heart.