Does she mind if you hold her at all? If not, then you'll have to try this at night. Starting with her foot and toes and going up her thigh, feel all along her leg (if you can, try to feel the bone) and see if you can feel anything a miss. You'll also want to be watching and listening to her reaction to see if she'll help you pinpoint where the pain is. If you're questioning anything, feel her other leg to see if it feels the same.
Also, move her leg, but don't put any weight on it. If she'll allow you, put it all the way down and gently move it as though she was walking. Then pull it up to the perching position. Again, you're watching for her reaction. She should react in some way if it's bothering her at all and hopefully you'll be able to see where the pain is.
I'm leaning more toward her having something pulled, but the first exercise is to hopefully rule out anything broken. The second is more of checking to see if something has been pulled. You might not find out anything from these though. Just watching the video, I am a little worried if it's something to do with her foot, like maybe she sprained it flying into a wall or something. (Her toes aren't curling in fully when she pulls up her, which is slightly normal for in this case, nor is she curling them as she walks. When she goes to step down, she avoids letting her toes touch the ground and puts all her weight in her heel. This might not be too out of the ordinary for an injury here, but it is making me question her foot a little.)
How it's been two weeks (and I'm assuming there's no improvement), it is pointing to a much more serious problem than the typical leg injuries I've seen. Usually there would have been some noticeable improvement by now, and often there is improvement within three days. You might want to take her fully off her feet for awhile and see if that makes a difference.
Here are some links from
@Eggcessive concerning chicken chairs:
https://www.backyardchickens.com/th...walk-one-leg-seems-fine.1603148/post-27282099
https://www.backyardchickens.com/threads/versions-of-chick-chairs-please.1166308/post-18356950
