What is the real name of Sunny in A Series Of Unfortunate Events?

The real name of Sunny Baudelaire in A Series of Unfortunate Events is Sunna (pronounced "Soona").

It's revealed in the book *The Vile Village* that Sunna is her true name. She was given the nickname "Sunny" by the Baudelaire parents, who thought it was "a more cheerful name for a baby with such a gloomy fate."