She was the sister of the architect Charles (Carlo) Bassi (1772–1840), who lived active in Sweden and Finland, where he had been raised since the age of eleven.
Bassi had a daughter, Johanna Fredrika (1787–1810), presumed to be fathered by Count Adolf Fredrik Munck af Fulkila, with whom she had a relationship at the time.
By persistent rumors, the count was said to be the true father of Gustav IV Adolf of Sweden, and Bassi's daughter was said to have a strong resemblance to the King, who might have been her half-brother.
When Count Adolf Fredrik Munck af Fulkila was exiled in 1792, Bassi left the Ballet and followed him to Rome in Italy, where she expected him to formally acknowledge their daughter and marry her.
In her marriage contract, Giovanna Bassi stipulated that her spouse should acknowledge her daughter with Munck as his, and that her great fortune should remain her personal and sole property.
She lived with her mother and her friend, the actress Elise Dubelloi from the French Theatre in Sweden, and she also had additionally three sons with Schön.