chicken looks ill- help :(

[kueblercoop]

I have a one and a half year old RIR hen that has been very docile the last few days. I first noticed a egg under the roost on morning, he has never laid here. The egg had some white substance on it and a TON of liquid was in the pine chips around it. I noticed the rest of the day she was not as active as normal. When I brought out greens she did not come when I called or run over with the other hens. I found her hiding in a corner of the run This morning I found the same puddle of liquid under where she sleeps and she is limping. Any ideas??? I want to help her very badly.