May I add to the post about the Stumble Stones? They are for anyone killed by the Nazis, not just Jewish people. You will find them for Communists, Socialists, Jehovah Witnesses, Roma/Sinti, and so many others.
If you are in Frankfurt, you may want to visit the Jewish Holocaust Remembrance Wall, with the names of almost 12,000 Jewish people deported from Frankfurt. There is also a WW2 bunker you could visit, with several historic exhibits inside.
https://initiative-neunter-november.de/
Going to Sachsenhausen, Ravensbrüch, Dachau, or Buchenwald are going to be very disturbing for your daughter too. 1000s and 1000s of people were killed in those places as well as horribly tortured. Suggest staying away from them and see or do something else that is not filled with photos of those who suffered and died.