I've read that the water and food should be near, but not so near the nest that she will dececate in it while she is eating. Good luck. Seems like an odd time of year to go broody, but then I am new new at breeding.
x2 The hen will come down when she needs food and water and to poo. It might not happen everyday but she knows what she is doing and you can just let her be. If you want you can put some food and water near her but it would be out of the nest so that she has to walk to it, otherwise she will poo in the nest.