Answer:
The irony about Jen's step-dad working for the Population police is that he broke the rule of the Population Police of having two children, by having a third child, and yet working for the organization.
Explanation:
'Among the Hidden' is a novel written by Margaret Peterson Haddix. The novel is about a society, where the Population Police has prohibited families for having more than two children.
Jen, just like Luke, is a third child in her family. Jen's mother had two sons before Jen, but she decided to have a girl on purpose, so they bribed the doctor and had Jen as a third child. The irony about Jen's step-dad working for the Population Police is that he broke the rule of having two children by having a third child, yet he is working for the Population Police. He is working for the organization, whose rule he has broken, so this is the irony.
