The Turquoise — Anya Seton

It was not that Fey Cameron was so beautiful. It was just that she seemed to be. There had always been something regal about her. Despite her humble background, she carried herself like a princess. There was another thing about Fey. She was gifted with second sight--a frightening and awesome power for one so young.
At 17, Fey left behind the impoverished New Mexican desert town and went off with a laughing, curly haired Irish rogue named Terence. With him, she crossed the continent in search of wealth and respectability--and love.
But Terry was only the beginning for her. She soon found herself a more illustrious benefactor--Simeon Tower--one of the most powerful men in New York. Soon the cream of Gotham society was welcoming this strange and wonderful creature, whose origins were mysteriously vague.
Only a handful knew the truth about her background.
Then one of them attempted to destroy her. . . . .