Who is Anne Fitzgerald from Cradle and All and what is their importance?

Anne Fitzgerald is the main character in Cradle and All by James Patterson. Anne is an intelligent and strong character. She was a nun but left the order and, after a short time in the police force, decided to become a private investigator. She is approximately thirty years old and remains unmarried. Anne is hired by the Catholic Church's Archdiocese in Boston, Massachusetts to investigate a string of occurrences. These incidents include devastating polio outbreaks in America and two apparently virgin but pregnant girls.