Opal-Eyed Fan by Andre Norton

1977 1st printing by Fawcett Press in good condtion with some stress lines along the spine. 
 
Was it a random storm or destiny's mischief that shipwrecked lovely Persis Rooke on Lost Lady Key? Persis couldn't be sure. Rescued by the handsome Captain Crewe Leverett and marooned on the darkly mysterious island with his strange sister and her beau, she was aware only of the oppressive superstitions of the natives who feared a strange curse--the curse of the opal-eyed fan.

Somehow she knew she had to learn the unspoken secret of the island and the truth about the fabulous Spanish lady who, years before, had left the infamous Satin-shirt Jack dead and then disappeared forever. But Persis was not aware of the evil that awaited her, nor of the romance that would endanger her until it was too late. . . .