As we do elsewhere in this learning guide, we're going to take this one in parts because the narrator changes between Part 1 and Part 2.
In Part 1, Julie is telling two stories, both from the first person point of view. She is the central narrator of her own story, in which she writes about what is happening to her day to day in the Ormaie Gestapo—but when she tells Maddie's story, she becomes a peripheral narrator. She still speaks in first person, but she removes herself from the story. Von Linden observes:
The English flight officer has studied the craft of the novel [...] [S]he is employing the literary conceits and techniques of a novel. (1.11.XI.43.4, 7)
Julie herself describes her narration as third person, but it's really first person peripheral because she continues to comment as herself. She says:
He wanted to know, then, why I was choosing to write about myself in the third person. Do you know, I had not even noticed I was doing it until he asked.
The simple answer is because I am telling the story from Maddie's point of view, and it would be awkward to introduce another viewpoint character at this point. It is much easier writing about me in the third person than it would be if I tried to tell the story from my own point of view. (1.11.XI.43.14-15)
This can get a bit confusing because the narrator splits herself into many people, so she is writing about her old self, Queenie, in the third person, but the narrator who is imprisoned in the Ormaie Gestapo is still in first person. Make sense? We promise it's not too hard once you get into the rhythm of reading.
Plus, if you can hang in there through Part 1, you'll be rewarded in Part 2, which is much more straightforward. Maddie writes this entire part in first person as the central narrator. She tells her own story, and she does so completely from her own point of view—there's nothing tricky about it.