From Petr Ginz and Anne Frank, move on to Helga Weiss, Helga's Diary: A Young Girl's Account of Life in a Concentration Camp, translated by Neil Bermel. She had lived in an apartment in Prague, friends went missing, Jews had to wear the star, school expulsions, and finally the deportations. She passed through Terezin, with its dirt, cold, and starvation and disease and fakery to dupe the Red Cross, with some 15,000 other children, of whom only some 100 survived Terezin; Helga went on to survive Auschwitz, see http://www.newrepublic.com/article/112805/helgas-diary-helga-weiss-reviewed-adam-kirsch.
She was liberated with her mother when Helga was 15. And they returned to their old apartment.
It has a self-conscious air, because much was written as a recollection later, when the ending was known. It lacks some of the pathos of those who do not know their ends as they write, but is authentic in its careful listing of horrors. More gripping then Weiss' descriptions are the diaries written in hiding, but the recollection process has its own value. There is time to explore more facets of events, take time to set them down right.
The Holocaust Museum lays out many identified children and their work, at http://www.ushmm.org/wlc/en/article.php?ModuleId=10007952: Miriam Wattenberg,
Also see Witnesses of War: Children's Lives Under the Nazis, 2005, by Nicholas Stargardt