When the diary begins, Anne is a fun loving and official teenager (she's just turned thirteen). Her most important decisions revolve arounf what she's going to do that day..... they're social decisions. As the Germans have already invaded her hometown, we see a girl who questions their treatment of the Jew, but only so far as to comment on how she herself is affected.
By October of 1942, Anne's family is already ensconced in the annex. In reading these excerpts, we see a young girl who is frightened for her family and their circumstances. Regardless of their danger, we continue to see Anne as a teenager. She's fighting with her mother, loving her father, aggravated with the other adults who've entered her life, studying, and feeling a bit put upon.
We also see a girl who's excited about growing up, mentioning becoming a woman, and being allowed to read more adult material, which was previously off limits.
By 1943, Anne is directly affected by adult worries.... food shortages and political news. She expresses herself through her writing, but she also misses having fun and being free. One moment she's acquired an adult outlook and the next she's a teenager again.... missing the fun of childhood, all while contemplating life, morality, and religious beliefs.
In early 1944, Anne is a few years older and wiser.... she's also falling in love. The fact that Peter is the only male available makes him an excellent choice. It also dooms him to failure, as I believe their circumstances don't allow much opportunity or time for daydreaming.... the faults and weaknesses of those living in the annex would have been quite apparent day to day.
By the end of the novel, we see Anne as a young woman. She's grown up, and she's a contributor to the daily grind. She participates in adult conversations and shares their worries. The entire situation has become not so much a bad dream ande something to complain about, but rather a fearful reality. Anne celebrates the good news and is frightened of the bad. She forges a new relationship with her mother, and sees her father as he is, rather than through the eyes of a little girl.