Problem with old hen

[dalae]

I have five ex-battery hens that were rescued and they are around three years old, they still lay from time to time, altogether they give me one or two egg per day. The thing that worries me right now is that one of them is clearly not laying anymore but she thinks she still does. I notices it a few days ago, she spends some time in the nesting box like she was getting ready to lay her egg and after a while she sing her ‘I’ve-laid-an-egg’ song but there was no egg underneath her. Today she was doing her pretend laying and she was disturbing the others hens. Next to her was one of my other ex-battery and she tries to go and nest with her, which she didn’t mind since the five of them share nesting box all the time. She then went back to her nesting box and one my chantecler, Emma, came in and sat in the nesting box next to hers. My ex-battery was trying to make a nest and moving the bedding around and when to steal some of the bedding in Emma’s box. She even went and plucked a feather off of Emma’s breast at which point Emma decided just to leave and she just went around the coop looking for a place to lay and she looked at the nesting boxes but didn’t dare to go back (and the ex-battery had settled herself in the stolen nesting box). So I’m kind of worried that she is going to keep disturbing the other hens that just want to lay in peace and such. Is there anything I could do to stop her from doing this?

Bonus picture of her all happy in her stolen nest.