Can you provide her a small coop with a small attached /covered run and put het apart? That way she can sit comfortable and stretch her legs in confinement.
A prefab coop like the prefabs they sell for 200 - 300 €/£/$ without a steep ladder is perfect for this purpose.
My broody types always need a few day from normal to broody. In the in between days they sit quite some time on the nest. But might still roost and run around too.
If I don’t want a broody this is the best time to intervene. Take away all eggs , take her out of the nestbox, make sure she roosts...