Only adds a little more possible evidence.
A note in a book margin indicates that Leonardo was working on a portrait of Lisa del Giocondo along with two other paintings (of whom or what?).
Vasari, the art historian and artist had stated back in 1550 that the subject was Lisa del Giocondo. Admittedly after Leonardo's death, but I would imagine that families who paid well were known to the artists of the time.

"All doubt" is not removed, although the combined evidence is good.

That rather weak and condescending grin on her puss has been hyped to death. A good portrait, I imagine Leonardo got paid well, but I think some of his other works are superior.