Retrospective
It's difficult to tell exactly what distance Miracle's speaking from, but she's definitely telling us this story from a position of looking back into her past. We can tell because of statements placed throughout the story that indicate that she's relating the story from memory. For example, when Part 2 of the book begins, Miracle says:
I don't remember much about my stay in the hospital, not those early days, at least. I don't remember how I got there. (18.1)
The fact that there are gaps in some parts of Miracle's memory demonstrates that she's telling us her story as she recalls it.
We here at Shmoop have an additional theory, though—one that doesn't specifically play out to the end of the book, but is nonetheless possible. At one of their sessions, Dr. DeAngelis gives Miracle a notebook to write the story of her life in: "He wanted me to write down everything I could remember, everything important to me" (27.19), she says. And later, the book resurfaces when Dr. DeAngelis asks why she hasn't started writing in it yet: "What was holding me back, he wanted to know […] I was stronger now. I could face the truth, all of it" (28.9).
So here's our theory: the book you hold in your hands is the notebook Dr. DeAngelis gave Miracle to write her autobiography in. Accepting the truth about her past has finally enabled her to face it and to begin writing her story. Pretty cool, huh? But if you disagree with us, feel free to argue your case—like we said, this is just our theory.