The Duchess Games by Alyxandra Harvey

Sometimes you have to break the rules to find your happily ever after.

The stern and proper Callum Winter, Duke of Tremaine, must marry. At least according to his mother.
Enter: The Duchess Games where ladies are invited to display their accomplishments in dancing, music and all social graces.
Caitriona Sparrow just wants to steal the duke’s signet ring to get her smuggling operation running and save the village from ruin. Options are scarce for a thirty-one-year-old spinster, her two younger siblings, four dogs, a cranky goat, and a one-eyed fox.
She might not have any pretty accomplishments, but she can sing sea shanties and debone a haddock in minutes. But between pianofortes and watercolors, Caitriona is shocked to discover that Callum remembers her from that passionate summer long ago and she has never forgotten him.

Cat might not be duchess material—but she’s the perfect woman to save Callum…and their happily ever after.
The only problem is that she has to betray him first.