Crush injury, hen not walking

[Eggstatic ChickyDoo]

Three days ago one of our ladies didn't return from free ranging. We have seen a few young fox down the road, figured one of them got her and decided not to free range for a bit (they have a good sized run). Today I found her up the hill, pinned under a rock. It looked like the rock was on her wing, but I pulled her out and she isn't walking. She also has blood on her beak, but no obvious head trauma otherwise. I'm leaning towards culling, but she did take water, so I'll give her a few minutes to see if she perks up.

 

[sourland]

I'd give her at least 24 hours unless she is in evident pain.

 

[Canadian Wind]

If you have electrolyte solution, give her that. She's probably seriously dehydrated after being stuck for three days. Easy on the food, mix it with the electrolytes. Don't give up on her!

 

[Eggstatic ChickyDoo]

Thanks for the suggestions and encouragement!
I offered electrolyte water, she wasn't interested, but she'll swallow if I dip her beak in it, so I've been doing that every 45 minutes or so. She's inside, in a box in a quiet dark corner, and dozing off and on. Her breathing is smooth and even, but still no indication of interest/ability to get up. I'd like to do a more thorough exam, but would also like to limit interactions/stress, so I'd like to make a checklist of things to check before I get started so I don't miss anything and have to bug her again. Other than obvious injury, what should I check for? If this was a mammal, I'd trim off the fur to get a better look, should I clip her feathers or is that likely to just stress her more?
I assume she has a leg or back injury- if it's not too severe I'll probably be looking at setting her up in a sling while she's healing, so I also welcome tips or suggestions for plans.
ETA- she's either getting more used to me or exhaustion is setting in, she isn't reliably waking up when I walk in now.

 

[Eggstatic ChickyDoo]

Update: I decided to put her down. When I examined her, one leg was bent at an awkward angle and clearly very painful and she wouldn't move either foot. In addition, she had extensive bruising on her spine.
Her injuries were too extensive and I felt that leaving her was just prolonging her suffering.

 

[LizGio]

It was for the best. I'm happy you found her and gave her a humane ending. Sorry for your loss.

 

[Canadian Wind]

I'm sorry. I'm glad she was with someone who cared though, instead of outside, terrified.