What is the theme in Galileo's Daughter: A Historical Memoir of Science, Faith, and Love by Dava Sobel?

One major theme in the biography, Galileo's Daughter: A Historical Memoir of Science, Faith, and Love Characters, is convent life. This theme is illustrated through Virginia's memoirs and letters to her father from the convent in which he sent her to be educated. Galileo's intent was for his daughters to be married, but as they were not legitimate offspring (he never married their mother), it seems that marriage wasn't to be.... possibly it was merely overlooked.