"Voyage on the Great Titanic: The Diary of Margaret Ann Brady" is a 1998 novel by Ellen Emerson White. It is part of the "Dear America" series of books, which are novels featuring young girls during significant periods in history; they are aimed at young adult readers.
Margaret Ann Brady is a 13-year-old in London, England in the early 20th century. She keeps a diary in which she writes about her life. Her parents died while she was young, and her elder brother has emigrated to America, so she is forced to live in an orphanage. Mrs. Carstairs visits the orphanage to select a travelling companion to accompany her on the maiden voyage of the Titanic in 1912, and she picks Margaret.
On the Titanic, Margaret spots an attractive young steward called Robert. They quickly become friends. Margaret writes at length in her diary about how much she enjoys the trip, the grandiose size of the Titanic and how extravagant the meals are. However, the ship hits an iceberg and begins to sink. Mrs. Carstairs escapes on a lifeboat, shouting to Margaret that they will meet again soon.
Margaret and Robert
Margaret scrambles below deck in a desperate attempt to find Robert. People she passes along the way insist she get onto a lifeboat, but she convinces herself there are enough lifeboats for everyone. She eventually comes across Robert, and they share an emotional conversation. Margaret begs him to come onto a lifeboat with her, but he refuses, as he cannot abandon his fellow stewards while the ship is sinking.
Spoiler: The Escape
Margaret runs back on the top deck and manages to escape on the very last lifeboat. As she sails away she hears the cries of the dying from the now-underwater Titanic. She writes in her diary that she cannot forget their howls of torment, nor forgive herself for not staying with Robert. She eventually travels to New York to meet up again with Mrs. Carstairs. There, she is reunited with her brother, with whom she moves in.