What are some character traits that describe Gretel in The Boy in the Striped Pajamas?

Gretel is Bruno's big sister. Though older, she's not necessarily wiser. She is as ignorant of the outside world as her younger brother, having also been brought up in a closed society where independent thinking is considered an act of treachery. When her family arrives at Auschwitz, Gretel is as puzzled as Bruno as to what the concentration camp actually is. It looks like a big farm, she thinks, except that there don't appear to be any farm animals about the place.
Nevertheless, Gretel does develop much greater curiosity in relation to her surroundings and to the war in general. She knows, for example, that the fence separating her family from the inmates is to stop the Jews from getting out. Thanks to her indoctrination she's become a full-blown anti-Semite. As far as she's concerned, the Jews are the Germans' enemies and that's all there is to it.
Ironically, Gretel's curiosity simply leads to even deeper ignorance rather than enlightenment. Closely monitoring the troop movements of the Wehrmacht may be a completely different activity from playing with dolls, but it's still just a fantasy world to her all the same. Gretel symbolizes the inability of millions of Germans to face up to the grim realities of life in the Third Reich. Moreover, she's abdicated her responsibilities as an older sister. Instead of acting as a guide and mentor, she's separated herself from Bruno, becoming more of a Nazi fanatic as the war progresses. In the figure of Gretel we see an illustration of how authority figures in Nazi Germany abused their positions to keep millions of people in ignorant subjection while they set about the systematic extermination of Europe's Jewish population.