Could the parents be using this as an excuse to pull child from care to go to someone with better hours, less closures, better rates, closer to home, or whatever other excuse parents come up with thinking it is in their best interest - in other words the complaint has nothing to do with peanut butter and more about how do we pull her. You mentioned having the older child didn't you in the sense you have a longer relationship with this family than just a new mom to care that I would come out and ask what is really going on. While you might not like the answer at least you will know where everything stands.