Who is Solitaire from Live and Let Die and what is their importance?

Solitaire is a beautiful Haitian born woman. Mr. Big says he is going to marry her. He believes she has telepathic abilities. She is a minor character in the story as she is held captive by Mr. Big throughout most of the story. However, when she shares a train cabin with Bond between New York and Florida the two fall in love and Bond considers saving her as one of his primary goals in defeating Mr. Big.