Although Patty is rich and Freddy is poor, both are outcasts because Patty is Jewish.
Patty is Jewish, which can make her somewhat of an outcast in the community. She is also an outcast in her own family, because she is considered a disappointment. Her father refuses to let her even go near Freddy because he is poor.
As soon as I closed the front door, he was standing there, telling me that he didn’t ever want to catch me playing with the Dowd boy, not ever again. I didn’t understand why. (ch 5, p. 63)
Patty does not understand, because he is very nice. Her father tells her not to contradict him and leaves. Later, when she is sitting by Freddy, he gets angry. At first she does not know why, until she remembers that she is not supposed to be with Freddy.
At one point, her father catches her with Freddy and starts to beat her savagely. Anton, the German soldier hiding in the garage, sees her and tries to come out and save her, but she yells at him to go away. Her father’s obsession with having her stay away from Freddy almost got Anton caught.