Not sure if my legbar is ill or not?

I have a Cream Legbar hen.  She was hatched back in may last year and lives with three other hens of the same age.  She started laying about month ago.  Her first two eggs were soft ones and then she laid a few normal eggs.  She laid a double yoke egg a few days ago then went back to normal then another softy.  She has always been the lowest of the pecking order however there has never been any pecking until recently.  Probably about four months ago I was slightly concerned about her as she was very dull looking and moping around, she soon got over it and has not done that since.  Recently however, one of the other hens has started picking on her.  I have used the anti peck spray which works for a few days.  She has a constantly pooey bum and her comb and wattles vary in colour some days being very pale.  Today the weather is very wet but the hens are still running around in it all looking slightly damp but the water is beading on them except Lucy who is wet through.  Today I have noticed that she is gapping (with no noise).  Other than these signs she acts normally and is lively.

I have wormed regularly since having them (they are nearly at the end of a course with flubenvet now).  They are fed with layers pellets and a little corn in the afternoon and occasional greens.  I use a small amount of cider vinegar and garlic in their water.  The house is cleaned well and there are no signs of mites etc.   

Can any one think what might be wrong with her?       (was thinking of brining her in to dry out, but she is not that tame so dont want to stress her out more)

Good luck, Gibbo
If you've ruled out mites and worms you might try taking her temperature.  You do this by feeling under the wing of one of your other (healthy) girls and then under hers to see if she feels warmer.
She could be moulting.  Are there lots of feathers around in the coop and the run?
It may be worth finding a local chicken-friendly vet to consult if necessary.  Not all vets are chicken friendly.
I'm sure someone with more experience will be along to give you more detailed advice shortly.

if she was laying a softee (either soft shelled egg or a shell-less egg) she would have been off for a couple of days. Are you sure what you saw was a yolk coloured poo and not the remains of an egg (they will usually eat broken egg, shell and the innards)? If she was off because of this she should revert to her old self quickly.

All is the same today.  Ive noticed that her vent is constanly palpating.  Could she have ann egg stuck? Dont fancy poking around that area!

I'm sorry gibbo but i don't like the sound of your hen.  It sounds very much like she's egg bound and maybe an internal layer which means she could easily develop egg yolk peritonitis, a very dangerous condition.  The fact she has had a very patchy laying history isn't good either and the dirty rear end are all indicative of a reproductive system problem.  If hens are trying to pass a soft or shelless egg they often look very depressed but rapidly pick up after they pass it.  The muscles which move the egg down the oviduct can't get a purchase on the egg so they go into overdrive and they can end up moving the egg the wrong way causing internal laying or a prolapse.  The scouring you are seeing at her vent may be indicative of this condition.

The wet feathers when all the others have beads on them is an indication she is not preening properly either which sick birds often don't do.  This is consistent with the inactive withdrawn depressed behaviour and being picked on.   She's clearly not well I think it's time to take her to the vets asap but unless the problem is due to some identifiable infection which can be treated the longer term prognosis may not be good.

HF

I thought i would wait a few more days before calling any vets and im glad i did, Lucy is looking much better and laid me an egg today! Perhaps she just didnt feel like it for a few days, i dont blame her!

Well that's good news she's probably perked up now the soft egg has been passed.  Just keep your eye on her as obviously she has some issue with laying given the history and soft eggs, as I said, can lead to being egg bound and internal laying.  Hopefully the dirty rear end will clear up and she will settle down to laying normally.
HF