Totally reasonable. My contract goes even further and states that the two week deposit is non refundable (just in case a family changes their mind at the last minute and leaves me in the lurch trying to fill a space) and it is to be applied to their child's last two weeks of care. It was just amazing how much better parents became at giving two weeks notice when they had already paid for those weeks. I also have a clause in my contract that states signing of this agreement is committing to a minimum four week financial agreement.