If you can have an Xray that would be best.
I'd examine the leg again for a break and feel the joint to see if the tendon is slipped.
I'd lean toward injury the way she's moving, but it's possible that something like Marek's disease is at play.
You can try stabilizing the leg to see if that...
Can you get a video of her walking?
Upload video to YouTube and provide a link.
https://www.backyardchickens.com/threads/how-to-post-videos.1588870/post-27000676
You mention the foot flops around? Is it broken?