Help with Dx....10+year old hen with leg problem

My easter egger hen started limping a little last week. I removed the ladder roost and rearranged things so that she wouldn't hurt herself getting up and down. And wouldn't you know it.........for all my effort, she now can't put weight on that leg. I hope its not broken or dislocated.
I have put her in a dog crate to decrease her mobility. She's fine in all other aspects, but can't put weight on that leg.
I've been giving her about 75 mg of Aspirin each day. Her "ankle" looks a little big.......but sometimes chickens' ankles are different from each other. When I held her to move her foot around, she didn't seem to mind......so I'm thinking its her hip..??
BUT......on the outer aspect of that ankle, its black. It looks like specks of soot, but doesn't rub off. I really don't think its relevant, but thought I'd mention it in case there's some funky disease out there. (or maybe that's what a chicken bruise looks like??)

I'm not taking her to a vet. I just want to make her comfortable, and hopefully allow her to heal.
Is there anything I can do to determine exactly where the problem is, and any suggestions on what I might do to facilitate her healing?

Thanks for your help.
I love my chickens.........Have only 4 left out of 17 and they're all 10 and 1/2. I want them to live forever.

 

Thanks for that link Flockwatcher. Its a good one.

I still can't figure out what her leg problem is.......maybe a hip problem, I just can't tell. Her foot looks a little weird, but I think she's holding it in a weird position to help distribute her weight.
I'll give her about a week, and if it doesn't improve, I'll take her to a local exotic bird vet. I just fear it might be something not fixable.
She's eating well and wants to move around, but is rather crippled. Nothing obvious I can see.
I am curious about the black on the side of her lower leg.
Thanks again.