I didn't see anything weird in the first video (but I'm terrible at spotting lameness) but in the second video, in the last 4-5 seconds, she looked like she was really head bobbing. Of course, since I'm terrible at spotting these things, there's probably something I missed. haha
She might also be just having a hard time with how you're lunging.
I know when I keep Lacey on a really short line and try to walk a big circle, she starts looking like she's moving weird (I guess maybe it throws her off balance or something?...) even though she's really 100% sound. When I let her go out a lot more and move in a much smaller circle myself, she lunges more comfortably. With your girl just coming out of "retirement"/prolonged time off, I wouldn't be surprised if she finds maneuvering a circle smaller than max lunge-line circle to be really difficult because she needs to build muscle.
In any case, she's sure a cutie!
Fabio - 13 year old Arabian/Lipizzan gelding
Rest peacefully, Lacey.