I have many years in Child Care and I owned my own Child Care Center for several years and I will pass on one thing I learned the hard way. If you accept funds from the state for child care services then any contract your parents sign is worthless. You can't make them do anything.
If you have a cash paying parent not pay or follow the agreements then you try to take them to court they only have to suggest it's discrimination. Your parents that use state funding don't have to pay you anything above their co-pay. If they have late fees, they don't have to pay them, the state will take their side, if they don't bring diapers and you charge them for them they don't have to pay, your contract with the state to receive funding has stuff in it to limit anything you can charge the parents they are paying for.
So be aware, you can lay it all out in black and white, discuss the various rules and charges but when it comes right down to it it's not going to hold water in court. Plus it wasn't notorized or filed in any legal way. It's just an agreement. Not a contract. My attorney said so when I needed to take someone to small claims court for non-payment of some late fees and then non payment because they were mad at me.
I had parents who would say things like "I didn't know that I had to pay late fees" and I would point to the signs posted on the wall by the sign in book and EBT machine. They ended up, of course, looking for another care provider that day but it wasn't worth my time and money for legal fees to persue it further. People are usually very nice and really try to take care of their care provider but some just don't get it and they will try to take advantage.