L'Express magazine reported on Thursday that the book will be called 21, rue la Boétie.
The address in Paris' wealthy 8th arrondissement was the location of an art gallery belonging to her grandfather, Paul Rosenberg.
Rosenberg was a gallery owner who also represented artists including Picasso, Braque and Matisse. He left Paris for the United States in 1940 to escape the Nazis and opened a gallery in New York.
The book will not be a "classic" biography, according to the magazine but, in Sinclair's words, "research into my family archives, childhood memories, portraits and stories from Bordeaux, Paris and New York."
Reports also circulated in December that Sinclair would be resuming her journalistic career by taking a top spot with the Huffington Post, which is set to launch in France.
The reports were neither confirmed nor denied by Arianna Huffington, the site's founder, or Louis Dreyfus, president at Le Monde newspaper which is partnering with Huffington in the venture.
Sinclair has remained popular throughout her husband's legal problems, ending the year by being named Woman of the Year in a poll by French women's magazine Terrafemina.