It's to hard to have multiple schedule. You'll never get a break. Everyone has to been on the same. I allow drop off only up till 9am. That way we can go do,our am activity while not waiting around for anyone and the kids all get an active morning so they are ready for rest by nap time. I would suggest having a drop off cut off. Otherwise you are going to burn out fast if you have to watch this little one and keep her quiet while the others are napping. Her parents need to get on board with your schedule not theirs. U can just say it nicely that you are finding it hard to accommodate more then one schedule and it makes the day flow smoother if everyone follows the same routine, etc. good luck.