Just a word on the legal side of deposit...Did you know that if someone gives you a deposit towards a service that never ends up happening, they are legally entitled to their money back?
If you give a wedding photographer a deposit and the contract or receipt states that the deposit if for wedding photography but then the wedding gets cancelled, then the wedding photographer must return the deposit. If however, the contract or receipt state that the deposit is so that the photographer holds that date to be available, the deposit is non-returnable in the event of a cancellation.
The same goes for every service based deposit.
Just make sure that the wording on contacts and the receipt for the deposit state it is for holding a day care place not for day care itself. Even if you clearly write "non-returnable" on the documentation, a deposit given for the reason of day care must legally be returned if that day care falls through, regardless of the reason the service wasn't provided.