What does Jonas's mother do for a living?
Jonas' mother works for the Department of Justice. She holds "a prominent position" (8). The position she holds seems to be somewhat like that of a judge, but because of how this community functions, she seems to have no authority to make judgements. There is a scene in the first chapter in which that becomes clear.
At the family sharing of feelings, which is community ritual and requirement, Jonas' mother takes her turn to share her feelings about her day. She describes a "repeat offender," (8), who has come before her on this day, someone who has broken a rule of the community once before. She expresses her concern about him breaking the rules a third time, since that will result in his being released. We don't know at this point in the story what release is, but whatever it is, it makes Jonas shiver, and "the disgrace was unspeakable" (9). Jonas' mother feels "frustration and anger" (9) because the punishment she had exacted on the previous occasion had been meant to be one that would have prevented another rule violation.
What is clear is that the hands of Jonas' mother are tied. She does not have the authority to prevent this person from being released if there is a third violation. As in the "three strikes and you're out" sentencing requirements that some states have had, in this community, it is "three strikes and you're dead." It looks as though a judge in this community has no judicial discretion to exercise. Jonas' mother is just as much a slave to the rules of the community as anyone else, and her "prominent position" (8), is a sham.