Grace Dalrymple Elliott was married at sixteen, divorced at nineteen, the mistress of two princes and various members of the peerage of England and France. Her longest relationship was with a man who refused to marry her but cared for her and her child all her life. She was imprisoned during the French Revolution and was a day away from execution when the Revolution ate Robespierre and the terror came to an end. She was buried at Pere Lachaise in Paris but her tombstone has been lost.
Apparently there wasn't a lot of material for the author to work from, other than Grace's memoir of her experiences during the Revolution and a questionable article in the Dictionary of National Biography. The author splits the narrative of Grace's life with full chapters about the men in her life, and fills up pages with sidebars about late 18th century life–a page detailing the process of getting a divorce by act of Parliament, for example, or half a page of slang for courtesans (many suitable for cat's names or crossword puzzles, ie Blowsabella, Grizette, Mab, or Wagtail).
Rather than a biography the book reads like Reader's Digest or a reference book, something one would dip into at odd moments, not read in a sitting. The writer also uses bits of fiction to illustrate places or people, which is a little disconcerting–romance novelists, especially of this era, tend to know their stuff, but the quotes in the book tend to be those heavy-handed passages of exposition written to prove the authors have done their research. The author also uses a lot of informal language, to what purpose I don't know, because it doesn't make me like her or feel closer to Grace (two chapters are titled "Mrs. Elliott's Excellent Adventures", parts one and two) and is happy to speculate wildly on very little evidence (Grace's granddaughter might not have married because she was either a lesbian or fat).
All of this is not to say it wasn't an entertaining read, but it's not quite a biography and not quite a coffee table book–the pictures should have been in color for that.