Ms Schacter I believe served as a warning from God just like Moishe the beadle was to the Jews. Similar to Moishe she saw the horror the group was about to go through and warned them and just like Moishe they ignored her. The fire she screamed of happened to be where Jews were burned alive by th hundreds.
Elie had a gold crown in his mouth. Gold being a valuable metal was searched for in peoples mouths. I think the Germans were attempting to strip all the value they could from the jews to help fund their terror.