A Sister to Beguile by Wendy May Andrews

Two nobles convinced love has no place in their future—until their hearts get involved.
Lady Graciela Sherton, the Earl of Sherton’s youngest daughter, shares none of her sisters’ ambitions for love or marriage—much to her mother’s chagrin. She is happy to spend the rest of her days at her family’s estate, steadfast in her conviction that boring is better. That is, until a threat to her family forces her from her complacent comfort zone.

Lord Alexander Sterling has no intention of marrying. Society might claim he needs an heir, but he’d rather die alone than subject another generation to a childhood like his own. Lady Grace is merely the inconvenient sister-in-law of the duke he is determined to do business with, until her calm nature and generous spirit have him realizing there may be more behind her pretty face.

When Grace and Alex team up to uncover a saboteur threatening the duke’s business, their own preconceived plans for the future are challenged by the conflicted feelings between them. They are both determined to keep their distance, but it’s getting harder to remember why.