Once Upon a Time - irony

The narrator of  Nadine Gordimer's Once Upon a Time begins with: "...I don't accept that I 'ought' to write anything (231)." The narrator sure does prove this point with her twisted children's story that she tells to herself. The narrator tells the story of the ideal family: successful, relaxed, normal, and one innocent child. However, the parents are paranoid from what the husband's mother, a wise witch, warned them not to take anyone off the street. Driven by this paranoia, the couple takes every measure to prevent the outside world from getting onto their property. They never felt satisfied with their measures. They installed a security system, built a higher wall, and installed a sort of barbed wire on top of their wall. The couple took all of these precautions to protect their child, but their is a sense of irony in the end. The boy climbs the wall, motivated by one of the witch's stories, and gets stuck in the wire. The parents took all of these measures to protect their son, but ironically these precautions end up causing harm  to their son. This story is in fact not supposed to be meant for children. Readers can tell this from the elevated diction such as implored or importuned. Also, the story does not relate to children. Children would be unable to find much a message to them besides not to climb into barbed wire. However, the message is more directed towards adults who feel unsafe. The message could be not to take excessive precautions for a nonexistent threat as the narrator thought of doing.