Keep in mind that the novel has stated at several points that the bank robber will do anything for their kids. Here, this means that they get what seems like the worst lot in their separation, as they don’t get to stay in the apartment or keep their job. The robber’s spouse, indeed, seems to almost weaponize the robber’s love for their kids by asking them to not make a scene—this is how they can exert power over the robber in the divorce. And not hiring a lawyer so as to not make a scene also means that the robber is going through this divorce alone, without legal counsel. And as the novel has already stated, adults don’t know everything, and so the robber might be more prone to making mistakes without some professional guidance.