If Harry has half a brain, he would have the girl delivered to the island by someone, not Marcone himself due to the coin, and then try to heal her. But I don't think he would ever use the girl as a bargaining chip. No, there is a chance that he knows how the Shroud works and it is not like that. But if healing is an option, I think Harry will call Marcone and do it for the woman's sake. No price, no deal. Of course, Marcone would feel grateful if it works.