The diary begins in January 1939 and chronicles her escape from bombing raids in her hometown, the disappearance of other Jewish families and the creation of the ghetto.
Spiegel and her sister, Elizabeth (nee Ariana), got separated from their mother, who was on the German side during the war.
Almost every entry of the diary ends with “God and Bulus will save me”, using the girl's pet name for her mother.
The book also features dozens of poems, and an account of falling in love for the first time with a boy names Zygmunt Schwarzer.
In July 1942, the year after the Nazi invasion of the Soviet Union, she was discovered hiding in an attic and murdered.
Her sister, unable to bring herself to read the diary, deposited it in a bank vault in the United States, where it remained until 2012.
The journal, which runs to almost 700 pages, will be released on September 19.
