Older chicken not doing well

[Sandwitch]

Hi I'm at a bit of a loss for what to do. I'm currently watching someones sick chicken while they are out of town and before I started watching them their parents noticed they were lame but with no signs of bumblefoot or leg injury. It's largely her left leg and it seems to randomly do better and worse. Today she hasn't left her little corner of the coop. I believe she's about 5 years old and a wyandotte hen. I think she was also having some trouble with her body wanting to start laying again I think she was trying to pass a soft shelled egg. It never felt like there was a normal egg stuck and she was able to poop some. Her feathers aren't looking super good either almost like she may be molting or kinda stringy? She's still rather chatty and I've tried giving her eggs nutridrench and some meal worms to give her some more protein support. I'm not sure what else I can really do at this point or even what the issue is

 

[Wyorp Rock]

Do you have photos of her?

Check her for lice and mites.

You may be right that she's trying to pass an egg. Ask her owners if you can give her extra Calcium for a few days to see if she passes an egg.

1 Calcium Citrate with D3 tablet each day or if you don't have that, give her 1 TUMS each day.