Shell-less eggs

[ChickenCrazy8]

I have a EE that is approx. a year and a half old. She has layed beautiful green/blue eggs and they have gotten gradually bigger and bigger. I got worried because I had a hen that was laying giant eggs and she started consistently laying shell-less eggs.
I was correct to worry, because my EE has now started consistently laying shell-less eggs. To the point where I saw her eating one day and she just squirted out a bunch of egg white. And this morning I noticed that she has the shell-less egg substance hanging from her vent.

I understand that laying shell-less eggs is a sign of low calcium. And I have a small container of oyster shells in their coop. I was also wondering if the reason she has started laying shell-less eggs is because of the addition of artifical light, to keep them laying through the winter. Maybe if I reduced/took away the artificial light she would start laying properally? I have started to slowly reduce it to see if it will make any difference.
It's just really frustrating because shell-less eggs are messy, you don't get yummy eggs, and it makes me worried that somthing is wrong with her

(even though she is drinking/eating fine)
Is there anything I can do to help her?
Sorry about such a long post
Thanks,
Zoë

 

[sepaditty1]

Maybe instead of a seperate calcium source you should switch to a layer feed for a couple weeks. Perhaps her instincts are a bit off & she doesn't realize she needs it.

 

[ChickenCrazy8]

The feed I give my chickens is supposed to be layer feed. Should I add oyster shells directly to the feed?
Thanks!