Thank you!! I'm so glad someone understood what I was trying to explain, that is exactly what is was, a soft, but strong partly formed shell!
She has laid 2 perfect eggs since, but now this morning, another egg exactly the same as the one mentioned...so it isn't a once off...
If this is a calcium issue, what more can I do to be sure she getting enough than just being sure she always has access to grit? Should I increase the scramble egg & crushed shell from twice weekly to every second day? Is there anything I can give her directly to boost calcium?
& if it isn't a calcium issue....what could it be? The example above about water belly scares me