When was her last egg?
I'd try giving extra Calcium for several days. You can find Calcium Citrate with D3 in the vitamin aisle of stores like
Walmart, CVS, etc. Give 1 tablet daily, just pull down on her wattles, pop the tablet into the beak and let her swallow.
Looks like she may have some fluid in the abdomen, hard to see. If she does, you can try draining it to give her temporary relief.
Likely she's having difficulties with a reproductive disorder. Which one is often not known unless you lose the hen and a necropsy is performed. Cancer, EYP, Internal Laying, etc. are all common in laying hen.
Sometimes a hen can get around like this for quite a while. If she's eating/drinking and not getting picked at, I'd leave her with her flock and work on her from there.