I've been doing some research and further examination of this hen - which we've called Limp Biscuit for the time being, lol - and we do believe it is bumblefoot! Her left foot has a dime-sized black/brown growth on it and she has all the symptoms of a bumblefoot'd chicken. I'm glad that you mentioned this possibly being the cause, because I was sure it was a bone/tendon/ligament of some sort, but now I am able to see why she is rotating that left leg so much, and it is to avoid stepping on the painful inspection. We have her separated for the evening and I have been looking up treatment options for the infection on this site. Thanks again for your guidance QueenMisha.
No problem! Bumblefoot is somewhat common and pretty easy to treat. Good luck with your hen!
