In the Time of the Butterflies, how does Maria Teresa's diary help her throughout life and how does her diary save her in prison?

As a young girl of 10, Maria Theresa keeps a diary as a way to record her personal secrets, as many young girls do.  In another diary she records her college years, and in a third her six months in prison. The early diary records events such as her First Holy Communion, and also indicates her love of "El Jeffe." Later she reflects in her diary that she no longer thinks of him "like God" as she once did.  In this way, her diary enables her to sort out the truth in life, to develop her understanding of the world.  In prison, we see her diary as her way of maintaing courage by recording thoughts of her family and anecdotes concerning her fellow prisoners.  It also secretly expresses her despair, anger, and terror.  Her prison diary also reveals thet her essential belief in the goodness of other is not destroyed despite her horrific treatment in jail. She uses her diary to help sort through the difficult decision as to whether to pass on to the inspectors the information she was tortured. In the end, she decides not to so so because she does not want the guard who was kind to her to get into trouble.  In many ways, Mate's prison diary functions the same as that of Anne Frank, the young Jewish girl hiding from the Nazis during WWII.  Both use their diaries as ways to maintain their faith in human goodness, to record their love of family and life, and maintain a sense of humor in spite of their suffering.