The Marquis, by Denise Patrick, is Book 1 in her Gypsy Legacy series and is the first free book of the year from Samhain. The content warning is fairly mild, though.
Book Description
One promise, two pendants...love that was destined to be.
Lady Christina Kenton's life is turned upside down when her gypsy great-grandmother gives her a pendant, along with a deathbed request -- Tina must promise to marry only the man wearing its mate. But Tina cannot bring herself to make the promise, for her late stepfather has already pledged her hand to his long-absent heir.
Jay Collings, now the Marquis of Thanet, returns to England after an eighteen-year absence to honor a promise to a gypsy who once aided him, only to discover he must break his vow in order to secure his inheritance. The last thing he wants is a wife chosen by the father he despised.
Tina's gentle strength touches Jay in ways no other woman has. And, unknown to them both, she holds the key to Jay's promise and his inheritance. But just as their fragile relationship begins to take root, the legacy of her gypsy blood brings danger to their doorstep.
Jay and Tina's destinies may be entwined -- but will they live long enough to fulfill them?
Warnings: The title contains mild violence at the hands of pistol-wielding gentlewomen, unmentionables found in public places, a bitter and vindictive old woman, some laugh-out-loud moments, and other situations that may shock women of Victorian sensibilities!