Historical fiction - Georgian period.
This is a preposterous premise, but it works because the characters are good and the story fairly rattles along. It starts in 1761 when twelve year old Deborah, woozy on a double shot of laudanum, is woken one night on her brother's instructions, and legally married to an outraged and emotional (drunk) sixteen year old boy. The following morning, she believes it to be nothing but a dream. Skip forward eight years and Deb is settled in Bath, enjoying society, bringing up Jack, her dead brother's child, and evading casual proposals of marriage. While in the woods with her charge, Deb comes across a young man, Julian, seriously injured in a duel. She patches him up, gets help, and saves his life.
It turns out that he's her husband. He remembers but she doesn't, so he's come back to claim her but intends to court her from scratch without telling her the truth. It goes on to get much more complex than that but much of the misunderstanding could have been avoided if Deb hadn't been left in the dark.