Casht the cheque and/or deposit it right away to prove that it doesn't bounce. The money is yours to spend but be cautioned that when they do leave care you will need to have enough money in reserve to cover the deposit.

I used to have it applied to the fist weeks of care too. Then for awhile I did first and last week. Now I am moving to last two weeks since it has become pretty much standard in my area to expect a deposist of two weeks fees. In essence what this means is that you are always being paid in advance since in your mind the deposit can go towards the start of care but then the parents are paying for the next week in advance so it is the same thing just to your advantage to make the money for the last weeks of care.