The Marshal and the Heiress — Patricia Potter

U.S. Marshall Ben Master stared down outlaws and desperados every day, but when he became the guardian of newly ophaned Sarah Ann, he faced trouble of a different kind. Word came that the 4 year old was lost heir to a Scottish estate, so he took her across the ocean, never expecitng to find a household divided by ambitions...or his head and body warring over Sarah Ann's remarkable aunt. Lisbeth Hamilton possessed a swift intelligence Ben's sharp mind appreciated, a tempting figure his fingers ached to carress and a future jeopardized by her niece's claim. When Sarah Ann's life became threatened, Ben's lawman instincts pointed to Lisbeth, despite the protests of his newly awakened heart.