Well if she wants to pay at the beginning of each month for the whole month then I would agree to that although I would try to compromise and suggest bi weekly but if she would rather give me a whee months feed at once then ok!!
I take a deposit equal to two weeks fees that is applied to the last two weeks if already commenced care. As well as I charge a $250/month Holding fee for start dates more then 4 weeks in advance non refundable and does not go to anything other then holding the spot (since its available now). If she was going to a centre daycare and the spot was available now she would have to pay full fees or lose the spot. Now if you are having trouble filling your spots then only you can decide what is going to work for you but if you have people lined up for the spot then that us more to your advantage.
Remember though if you negotiate with her now she will believe everything is up for negotiation ..... Been there .... done that .... And termed because of it !!!