In the Secret Annex, Anne not only writes in her diary but also writes short stories, and she has a special notebook in which she copies beautiful sentences, on her father's advice. Of course all the Annex occupants are curious to know what Anne is writing, and once in a while she reads them a story of her own in the evening. She does let anyone read her diary, however. On Monday September 21, 1942 she wrote:

"I'd just finished writing something about Mrs. van Pels when she walked into the room. Thump, I slammed the book shut.
"Hey, Anne, can't I even take a peek?"
"No, Mrs. van Daan."
"Just the last page then?"
"No, not even the last page, Mrs. van Daan."
Of course, I nearly died, since that particular page contained a rather unflattering description of her. There's something happening every day, but I'm too tired and lazy to write it all down."

Quoted from: Anne Frank, The Diary of a Young Girl. The Definitive Edition Viking, an imprint of Penguin books Ltd. London in association with The Folio Society 2006.