How many letters are in goodbye?

Rhea Farrell is seventeen, but still carries the scars of a terrible childhood accident, one which left her with only one arm, but also without her mother. She barely remembers her mother, but as a child Rhea would write letters to her in an attempt to let go of her pain. Now, with her father's alcoholism getting worse, Rhea runs away to New York City and turns to writing letters to her mother once again to get her through the tough times--of figuring out what her life should be about, and figuring out her confusing sexuality.