So, why not just follow the policies that you signed off on? I get that you're feeling like you just keep on receiving letters and it's getting you down, but how must she feel if she feels the need to continuously send you formal reminders of every day policies? All of my clients receive the same expectations. No one is more special then the next. I have a policy handbook, and if a parent forgets, I remind, but they are usually respectful enough to clarify the policies with me before assuming something is ok. I have only ever had one client who continuously disregarded my policies, and that business relationship unfortunately ended with me terminating their services.
Apart from the reminders, is she friendly? Does your child have a great time, doing fun things in her home? Is your child loved, well cared for in a safe home away from home?