Miss Elspeth's Desire. The Search Duology, #1

Elspeth Forster, the eldest spinster sister and part owner of Forster Shipping Line, has never known passion. But that's about to change. After their youngest sister marries, Elspeth and her middle sister Isabelle decide to use their ships for more than just business by taking the adventure of a lifetime. In India she might find a man who can teach her all the things that will keep her warm in her advancing age.
But she never expected that an unscheduled stop would put her within Aeddan Fitzsimmon's sights. Returning from a top-secret mission, English spy, Aeddan Fitzsimmons, finds passage on the Zephyr, a vessel in the Forster fleet. From the moment he steps aboard, the statuesque redhead entices him like no other ever has. Now in India he has a new mission: keep the elegant Elspeth safe from those who'd use her connections for their own purposes, while wooing her into his bed.