Who is Claudette Blum from A Thread of Grace and what is their importance?

Claudette becomes known as Claudia Fiori and later Claudia Cicala. She is a young Belgian Jewish teenager who is on the run in Italy with her father, Alberto Blum. Her mother and brothers were put on a train by soldiers and never seen again. She and the ailing Alberto are taken in and cared for by various Italian farmers. In the roughest possible conditions, Claudia and her father manage to survive the winter in the mountains. She meets and marries Santino Cicala, a young soldier who is killed by German soldiers when he confesses to killing five German soldiers who were raping a girl, Maria Avani.