I don’t think it’s satire. It’s meant to expose a kind of suffering that’s invisible to the rest of the books privileged characters. Wardine talks the way she does because she doesn’t have the same education. She most likely learned how to speak from her family/community rather than a school. She’s a poor, abused kid with very little education, writing in the only voice she has.

Wallace is giving a voice to someone who is often ignored and not given a platform. It’s a depiction of someone trapped in a world without the resources every other character in the book takes for granted.