http://www.justanswer.com/bird-vet/6vqvz-chicken-dreadfully-swollen-belly-hardly-walk.html
https://www.backyardchickens.com/threads/straining-chicken.921134/
trying to find you something that will help.... swollen belly...? worms...? an egg that didnt drop and got stuck somewhere it shouldn't...
Unless someone comes along that knows about these things...
If you have the time.... I'd give her a few 20 minutes soaks a day...
Maybe try dulcolax ....? they say it doesn't harm the birds, we use it for an impacted crop.... is she pooping...? maybe send the video to a vet, see if...