What's wrong with my chicken?

We just received 6 hens about a week and a half ago from my grandpa. We don't know too much about chickens yet, so I'm not quite sure what is wrong with her... Last night my husband went to close up the coop, and noticed her sitting/laying on the ground and not up on the roost. This morning when he went to let them out, she was still up on the roost, while all the others were on the ground and ready to be let out. They all rushed out for the morning treats, and she just stayed right there. So my husband placed her outside, and she just waddled over into the long grass and sat down again. They are pretty flighty birds since my grandpa never spent time with them, so they won't let us get very close to them or touch them. We don't know which hens lay eggs either, yet. Not sure if she's egg-bound or what is happening. It's been hot the last few days here, but the other chickens are doing fine. They're all a little over a year old, so I doubt she's just having a hard time dealing with the weather. Could she have an injury? We can't really afford a vet, so we're just not sure what to do.
Any ideas?

 

Ok, so I just asked my hubby, and he said there is bright green diarrhea poop stuck to her feathers... I am off to get a kennel from my brother-in-law and see if I can get her in there.

 

I have her isolated... she is barely moving... laying down and closing her eyes... not talking... not eating or drinking. When I've looked at her poop, she has liquid green stuck to her feathers, but what I've seen coming out is runny and white. Just kinda squirting out periodically. I can't feel any hard mass like a bound egg, but now I'm wondering if the egg broke inside? I tried to look for mites around her vent and didn't see any. Her nose doesn't look like it's runny either. The hubby did say that either yesterday or the day before he went to gather the eggs, and one of them had been completely eaten (we can't tell which one(s), but they have a bad habit of pecking/breaking/eating the eggs). Would this cause issues inside her, if she was the one to eat it? Maybe the shell is now stuck and won't let her pass any more eggs so the egg broke? I honestly don't know. I don't know what to do or how to help her! Should I try a warm bath? She is acting like she is dying... just kinda letting her head fall and closing her eyes... only opens them for a second when you touch her or try to move her.

Oh, one other thing: She is sort of favoring one leg. When I tried to get her to stand, she leaned to one side and seemed to limp while she took a step. I looked and one of her nails/talons is broken and hanging there. Would this injury cause all of this? I don't know if it's an old injury and she's just leaning/limping because she's in pain inside, or if she is now laying down because of her claw. But I wouldn't think that white runny poop is good... or that she wouldn't be eating or drinking...

 

Bump

 

Went to the feed store and got some powder to treat for mites. Also got some vitamin/electrolyte stuff to put in the water. She hasn't ate/drank all day... has stopped pooping as well. Had to feed her some of the water with a medicine dropper. Keeps tilting her head to the side/laying her head down, like she's just giving up. I can't figure it out if it's internal, or if it has something to do with her toenail/claw that is ripped. You'd think that if it was the toe, that she would still be eating/drinking a little bit more alert, but just limping or something. Hopefully tomorrow we'll see some improvement?!