The children of the Holy Roman Empress Maria Theresa form a large part of the cast of Antoinette's Sister by Diana Giovinazzo. This is no surprise: They numbered enough to make up a team roster for many sports, with 10 of 16 surviving to adulthood. Of these, the most famous are her sons Joseph II and Leopold II, both of whom inherited the Holy Roman Empire in turn; Maria Carolina, Queen of Naples and Sicily, around whom Antoinette's Sister revolves; and Marie Antoinette, Queen of France.

Known for the educational reforms implemented during her reign and sometimes called "Europe's mother-in-law," Maria Theresa ensured her family's lasting political power by arranging for advantageous marriages between her children and the heirs and heiresses to thrones, regions or fortunes. Between the four children mentioned above, for example, Maria Theresa managed to ally Austria and the Holy Roman Empire with the kingdoms of Parma (through Joseph II's first wife, Isabella), Bavaria (through ...