Who is Vilma and Signora Sinino from History: A Novel and what is their importance?

A cat lover who lives in the Ghetto, Vilma tells of horrific news she is hearing about the Nazis and their treatment of Jews in Poland. Signora Sonnino sells clothing and listens to the Fuhrer's voice on the radio, and has some understanding of what is coming. Both women are more aware than the average citizen in Rome's neighborhoods about what Hitler is actually planning and doing to the Jews of Europe.