Sweetbriar by Jude Deveraux

Linnet Blanche Tyler plunged into the Kentucky wilderness, leaving behind the remnants of her life in London. But a savage Indian attack on the wagon train wiped out her fellow travelers, and left her alone in a harsh land at the mercy of a fierce Shawnee tribe.

When a handsome young brave, Devon Slade Macalister, claimed her, in perfect English, as his own, Linnet knew she was safe. Until a jealousy of a powerful chief , Crazy Bear, forced them to flee on a hazardous journey, fraught with peril and treachery...a journey that threatened both their lives, and their very special love!