On Friday evening, the sun was out and it was a lovely evening - we got home early from work and let Daphne out onto the lawn to sit in the sun and eat grass, mealworms and sunflower seeds, whatever she wanted.
She also had some time wrapped in a towel and cuddled on the sofa with Helen, before having a bit more time out in the sun.
When it was time, we took her to the vets (this time a younger guy) and explained how her leg hadn't got any better - the vet was lovely, kind and gentle with her, took our word for things so didn't unnecessarily stress her out and actually seemed to want to find out the root cause of her problem.
He quickly pointed out that she had restricted blood flow in her leg - he showed us how one foot was cold, the other warm, and also the normal one had a pink-ish tinge to the skin, the other didn't. He said at that point that it wasn't a simple injury or hip problem, which is why the meds hadn't really worked (other than for pain relief) - the problem was something pressing on the main artery to her leg. He explained that it was likely to be a tumour or cancerous growth, and that even though they could x-ray to confirm this, it wouldn't really change the outcome, and it would just pro-long things.
We took the decision to have her humanely put to sleep - we were both gutted as she was an absolutely lovely little (huge!) hen, but it was for the best.
She's not in pain now.