If you’re talking 6-months old rather than 6 years old, “Go the fuck to sleep” [1] is a good one :) Audiobook version by Samuel L Jackson to boot…

Yes, I suspect the book isn’t quite what you’re looking for, but it is actually a very funny (if adult) book, at least the first time you read it…

[1] https://www.amazon.com/Go-F-Sleep-Adam-Mansbach/dp/145584165...

I like this one by the same author: https://www.amazon.com/Go-F-Sleep-Adam-Mansbach/dp/145584165...