Hen laying thin, light colored shell eggs, why?

[TheCluckShack]

I have a hen who lays eggs like this. We've also noticed she's one of our most prolific layers (practically daily) and every 5-14 days, with no changes to diet and plenty of oyster shell, lays a thin shell/no shell egg. I've been reading lots of threads tonight and think it may be just be a problem with her shell gland and definitely specific to just her, the others lay just fine. Incidentally, she's the Queen Bee and the scrawniest and bossiest of the entire small flock!

Mine too! Right down to Queen Bee part!