Anna was baptized on 11 August 1738 in Bologna as "Anna Ioanna Lucia, filia Hieronymus Boni et Rosa Ruinetti", some time after her parents had come back from a tour that included performances at Anna of Russia's court in St Petersburg. On March 8, 1743, at the age of four, she was admitted to the Ospedale della Pietà in Venice as a student; that she had a surname indicates that she was not a foundling as were most of the Pièta wards, but a tuition-paying pupil (figlia de spesi). She studied with the maestra di viola, Candida della Pièta (who herself had been admitted into the coro in 1707).