This is a decision that has its pros and cons. The pro is that if you move her, you'll have the nest box back and the other hens will stop laying under her, so you won't have to worry about what egg was laid when and she won't have some hatch and get up and then the other partially developed eggs with die, etc etc.
The downside is that if you DO move her, it might break her. Or she may just refuse to use the new nest and go back to the old one and leave all the eggs in the new nest to get cold and die. If you do decide to move her, I would do it at night and block her in the new nest for awhile to encourage her to stay there. I've moved broodies before and had no issues, but I've also broken a broody accidentally just by changing the bedding in the coop. It all depends on the hen herself.
Maybe what you could do is simply block the nesting box so the other girls can't get in there, and let your broody out once a day to eat and drink. Also, putting some golf balls in the other nests may entice the other birds to lay there instead.