Latest Laurie Graham

Well, not really the latest, but the latest one that I have read. Gone with the Windsors is about the rise of Wallis Simpson and her eventual relationship with the King of England. It was very entertaining, although I did feel a little uncomfortable at times with what seems like a very calculated and manipulated relationship. The descriptions of the lives of the wealthy in those times sounded so frivolous, but the book contained some very interesting debates about the politics of that time. Laurie Graham's books all sound very factual, but there is never a bibliography included. I would like to know how much of her books are based on fact.