i have a light sussex chicken which in now about 8 months. sine buying her when she was 18 weeks she has never laid a normal egg. when i clean out the coop i often find what looks like bits of egg yoke. i have witnessed several times in the past unshelled eggs in the coop. she has laid 4 or 5 shelled eggs but these are either soft shelled, or the shell is very thin a breaks very easily or very rough and dry. her comb and face colouring is often much paler than the rhode island red and maran which are laying one egg daily without fail. ?
are you adding grit or oyster shell to her diet? sounds like she may have a deficiancy in her diet perhaps?
the bits of egg yolk could mean you have an egg eater
Oops....I second that. Get there early to get the egg before she gobbles it up. Do you keep her on her own? If so, get a couple more, chix are a flock bird and happier that way.
We occasionally have a soft shelled egg and they are easily broken by the hen. It could be that she is eating the shell as she has a calcium deficiency.
The fact that the comb and face are pale is a sure indicator that the hen suffers from an ailment. The soft shelled eggs are a secondary result of her being too sick to completely finish the egg process. There are far too many possibilities to even start guessing what's wrong. Short of getting expensive professional advice, there is not a lot you can do except hope it will get better - occasionally they do.