I've had one caught by the tail by a young dog that looked bald and a bit red in the bum/back for a few weeks but it grew back and she settled down in a day or two.
I've also had a hen that was hopping lame after a log fell on her leg and trapped her - I kept her in a separate run for a few weeks til she was able to carry weight on the foot again and I wasn't sure if it was broken initially but as she was eating I gave her the chance and she became very tame and is still here, right as rain, a year or more later.
Personally if she's not got an obvious break ie at the wrong angle, I'd separate her into a small area where you can feed her without her having to move far, and see how she goes. It took mine quite a while to recover so sprains or bruising are obviously not overnight matters for hen legs. I'd take eating and drinking as the markers of hope, myself, and let her have time as long as those are still normal behaviours.