In what ways do the the sentence structures and the choice of words sound like a teenage girl telling her own life?

The first person ("I") retrospective narrative is constructed with episodes. The prime person in Annie John is, of course, Annie. Therefore, the Antigua shown the reader is that which is filtered through Annie. There are eight episodes highlighted in the chapter headings. During each episode more information is given about Annie. The timeline jumps but there is a steady progression from Annie as a young girl to her departure from home as a young woman.

This narrative, however, is ironic because an adult Annie establishes the reality of the story as if it was the perspective of little Annie. In other words, Annie knows her own story's outcome but tries not to reveal this. The novel opens by literally noticing figures in a distance and also by placing the story at a distance, "during the year I was ten." Thus the effort on the part of the young Annie to show her mother as an Old Testament deity is offset by the adult attempt to reconcile. The mother remains beautiful and loved though the literal story might say she is simply left behind.