Just had a thought, on top of all the disturbances the poor girls have had these past months, we are now experiencing only around 5 hours of darkness plus it's a lot hotter than usual. I've just read this can have a damaging effect. So I've had to make them go inside thier coop, leaving the door slightly open for what little air flow there is . My other girl stopped laying for 2 days, since I put them to bed she started producing eggs again.