Grace Elliot

The Duke of Orléans’s ex-mistress, a spy for the British Foreign Office

Grace Elliott is a professional mistress from Scotland, whose past lovers include the Prince of Wales (later to become George IV). She was once the mistress of Philippe, Duke of Orléans, and they remain on intimate terms. She passes documents and political gossip to the British government.

Journal of My Life During the French Revolution  by Grace Dalrymple Elliot
On this day 1823: Grace Elliott, Scottish courtesan and spy, dies
The story of Grace Elliot's incredible life – from high society to spy to author | The National
Grace Elliott - Wikipedia