Carlotta

From Memory Alpha, the free Star Trek reference

Carlotta was a holographic character in Kathryn Janeway's Leonardo da Vinci holoprogram.

She was from Florence and posed as a model for the maestro and his disciples.

When The Doctor had to hide in the holoprogram in order to avoid detection by the Srivani, he posed as a painter and attempted to portray Carlotta. (VOY: "Scientific Method")

Carlotta was portrayed by an unknown actress.