The Highland Guardian (Lords of the Highlands Book 3)

A Goodreads Best of the Month pick!
He has sworn to protect her... Captain Reid MacKenzie, Earl of Seaforth, is a man of his word. During a harrowing battle at sea, the heroic Highlander makes a vow to a dying friend to watch over the man's daughter. His plan: send the child to boarding school as quickly as possible so he can continue his mission. But Reid's new ward is no wee lass. She's a ravishing, fully grown woman, and it's all he can do to remember his duty and not seduce her himself.
But he might be her greatest threat... Miss Audrey Kennet is stunned by the news. First this kilted brute tells Audrey her father is dead, and next he insists she marry. But as Reid scours England for the most suitable husband, Audrey soon realizes the brave, brawny Scot is the only man she wants--though loving him means risking her lands, her freedom, and even her life.
Lords of the Highlands series: The Highland DukeThe Highland CommanderThe Highland Guardian