Susanna was Silvia Bellini's most trusted lady-in-waiting when Silvia was the Duchessa of Bellezza. During Silvia's pregnancy, she helped the Duchessa conceal her condition and later aided the midwife, Maria Maddalena Landini, during the birth of Silvia's daughter, Arianna. As a result, she is one of the few people who were aware that the Duchessa had a daughter.
Following a second assassination attempt on Silvia, Susanna discovers that her mistress survived the attempt on her life. She pledges to continue serving Silvia and discreetly removes Silvia's personal effects and valuables to help begin Silvia's new life in Padavia as a wealthy widow. Before leaving, she also advises Arianna, who has become the new Duchessa of Bellezza, to retain the existing staff at the Ducal Palazzo.
Throughout City of Stars and City of Flowers, Susanna remains Silvia's most trusted servant. She moves back to Bellezza with her mistress when Silvia publically marries Rodolfo Rossi and returns to the city.