Sorry, I have been so busy this weekend.
I popped her on the eggs on wednesday afternoon, in her own little house, with food & water & a little run. When I got home from work on Thursday at 2.30, she had escaped & got back to the main coop & was in the nest box there. I have no idea how long she had been off. Anyway, I put her back & made it more secure. Since then, she hasn't moved from the eggs.