A Spinster by the Sea (The Siren's Retreat Quartet #3)
Grace Burrowes

Augustus believes Anne is far better off without the buffoon who jilted her, but knows polite society will hold the lady accountable for the failed wedding... weddings, rather. He proposes to show Anne marked attention at the house party, in hopes that a ducal suitor will prove to the gossips just how lovely Anne is. Alas for Augustus's brilliant scheme, the best laid plans of dukes of damsels, oft go awry!