In The Boy in the Striped Pajamas, Bruno refers to his sister Gretel as "The Hopeless Case." Bruno is the narrator and so the story is told from his perspective and Gretel's key characteristics or attributes are seen from his view. When he first learns that the family must leave his beloved Berlin, he wonders why, if it's because of Gretel (which is the assumption he makes), the whole family must suffer. He also wonders, when he realizes that the family really is moving, why she doesn't stay behind because she is "nothing but trouble" (chapter 3). Bruno is quick to point out Gretel's shortcomings which include her inclination to spend too long in the bathroom, her tendency and that of her "unpleasant" friends to tease Bruno and her unnerving doll collection. Although they seldom show any affection for each other, both children do agree that their new home is "horrible."
Gretel reveals her insecurities when Bruno shows her the "other children" because, from this distance, they do not look friendly. These are the children in the camp, in the far distance and which children Gretel and Bruno are not supposed to acknowledge or show any interest in. Gretel is shocked that there are any children at all and she does have some sense of foreboding when she sees the barbed wire and sharp spikes that surround the camp. She does try to explain that this must be "the countryside' and the camp must be a farm. She is determined not to let Bruno get the better of her but is prepared to concede that her vision of the countryside is unlikely.
Gretel lacks understanding and is very self-absorbed. Rather than recognizing the plight of the children, she considers how dirty they look and is glad that she does not have to play with them. Gretel pretends to be older than she is but her actions belie her immaturity. She shows little respect for Maria, the maid and when she does befriend Lieutenant Kotler this only serves to increase her interest in the Nazi party and she seems to have little concern for what she has seen on the other side of the fence or for anyone else's concerns, except her own.