Sick chicken - lethargic, not eating, pale liquid from mouth

I think I noticed subconsciously yesterday that one of the girls wasn't moving around as much, but it was obvious this morning. She was sitting on the ground and didn't get up when I approached, and let me pet and handle her. She had a little white poop in her tail feathers and on the ground behind her - very small and no black part. When I nudged her to one side, she slightly lost balance.

This evening she is in a different spot, but still sitting motionless. Her crop is empty. I turned her onto her back to feel her vent and some pale liquid dribbled out of her mouth. It seemed like she didn't have much energy to raise her head. Her vent is clear - no egg obstructing it.

I wanted to check here in case I was missing something obvious to do to help her. If not, I will dispatch her tomorrow.

Does the liquid smell sour or like alcohol?

Didn't think to smell it, and it's dark now so I'm not sure I could find the spot.

Hope things have a happy ending and she's right as lemon drops in the morning.  

It could be any number of things.  It depends how far you want to go.  If the chicken can still eat or drink, and isn't showing immediate distress, I'll isolate them and give them a very high dose of poultry vit in their water.  About 3 times the normal strength for the first few hours, then give them regular strength from there.  If it is has added electrolytes, the better.  9 times out of 10, they get better on their own after a few days.  If she won't eat or drink, there are heroic efforts you can make, but these often don't work unless the cause is a physical injury.  

It sounds a bit like sourcrop, which would make liquid come out her mouth.  If you smell her breath, it will be sour or alcoholic.  

It also sounds like sour crop to me. How is she feeling today?

Good news! She is feeling better today. She was still sitting still when I approached, but then she got up and ran away from me. I caught her and tried to smell her mouth, but my nose is stuffy from allergies and I couldn't smell anything. But she held her head up while she was on her back and no liquid came out. After I put her down she drank water and walked around.

thanks for the update.  Hope she continues to mend.

I had a rooster do that once from eating too fast. He got a great big gob of pellets caught in his throat and foam and drool were running from him mouth.  He got it down, I guess after the pellets softened up and he was fine.  Glad to hear yours is doing better.