Theories also abound that the sitter was happily pregnant, or affected by various diseases ranging from facial paralysis to compulsive gnashing of teeth.
Known for controversial claims such that letters and numbers are hidden inside the Mona Lisa painting, Vinceti has based his search in the convent on documents found by Pallanti some years ago.
One document is Francesco del Giocondo's will in which the merchant asks his younger daughter, Marietta, to take care of his "beloved wife," Lisa.
At that time, Marietta, one of Lisa and Francesco's five children, had become a nun, thus she brought her mother to the nearby convent of Sant'Orsola.
Lisa died four years after her husband's death, at the age of 63, according to a document known as a "Book of the Dead," found by Pallanti in a church archive.
"Lisa di Francesco Del Giocondo died on July 15, 1542 and was buried in Sant'Orsola," the document states.
The record notes that the whole parish turned out for her funeral, showing that she was rather famous among Florentine society.