Standing & Walking Like A Penguin but NOT Egg Bound?

[Wyorp Rock]

3 days ago my 7mo old hen came out in the morning walking and standing like a penguin with a slight limp. On solid surfaces such as concrete or my vinyl flooring, she cannot stay balanced and her legs try and splay every which way.
She is not egg bound and has laid every day. She has no fluid in her belly and is pooping and eating super well. She wants to be super active and out with all the others and is very unhappy if I put her up. But I’m afraid she going to get even more seriously injured.

Can you post the video?
Upload to youtube and provide a link.

Not sure what's going on there, I would keep her off the concrete and vinyl flooring since she has trouble standing on those.

There's so many things that could be causing her issues - from injury to deformity to disease.
I'd be inclined to offer vitamin support (400IU Vitamin E, 1/4 tablet B-Complex) daily for a couple of weeks.
In addition to the E and B-Complex, I'd give her 600mg Calcium Citrate with D3 for 3-5 days.

Keep her eating/drinking well. Check to make sure her crop is emptying.
If she can be outside with the hens and not the rooster, then I'd also consider letting her out to do her chicken thing instead of being separated from the others. Of course, closely monitor her, if she gets worse or starts to get picked at, you notice she's not eating/drinking, then pull her aside and give her extra care.