a common problem in setups using rows of nestboxes. the only 'cure' is isolating her in a nest.. if she will accept you moving and confining her and eggs in a kennel then that will work. Some hens refuse accepting a nest that looks radically different from her usual choice of nestbox though... I use covered cat litter boxes for that reason, if I want to move a broody hen, I just pick the whole cat box and put in isolation after dark. Same nest, slightly different location- nearly all accept this.
if you screen off her nest box, I'd prefer to take her out once a day for toilet and food/water break instead of just putting food/water and shutting her in. She needs to exercise too, so her muscles don't atrophy too much. Screening her nest off also prevents other hens from bothering her, which has the high risk of eggs getting broken.
they do not know if eggs are fertile or not like the person above said.
