Just wondering why do you need to prepare food? Can your nanny buy the food items.
I leave my daughter at a nanny's place. I will pay her $50 so she can use that to buy cereals and other items.
Of course if i buy certain foodstuff in large items i will pass half to nanny.
I also bought a toyogo drawer set in which my nanny can keep all the clothes/toys/diapers/ toiletries/ nappy cream/baby clothes washing detergent and dishwashing liquids.
I also gave a tub and baby high chair.
So on daily basis i dont have to do any washing of clothes that she wore at nanny place. Saves a lot of time clearing, cleaning and packing. [seriously once you start working you will be firefighting with time]
I send my gal and pass my nanny a notebook for her to record essential things she did for the day like naptime, milk feed etc...everyday.
Hope this helps.