When I approached Bob he was more than happy to answer the following questions in Vet's Corner. These are subjects that may affect any one of us from time to time. Having professional advice could be the means of easing or eradicating any problems that may occur in your situation. Not allowing a keen hen to nest would have few adverse effects on her health. However, be aware that where there' s a will, there's a way.
Avicultural literature is full of stories of birds nesting on the ground and other strange places.
Having said that, I would be more concerned about allowing such a hen to breed continuously. The drain on her body resources, especially calcium, can be disastrous, with reproductive problems such as egg yolk peritonitis, retained eggs and egg binding , as well as generalised weakness, the likely consequences. Her breeding life is likely to be reduced considerably. Weighing up the balance of likely risks, I would definitely opt for resting such a bird. To achieve a better breeding result I've been told to put birds on a straight seed diet with no additives for 3 months prior to the breeding season, then to gradually re-introduce the usual greens, fruit and vegetables.