The stumbling came from some sort of neurological disorder. She wasn’t stumbling. She had to be lifted into the van. She was incapable of walking.
Yes, you can see from her stiff, toe-pointed right leg in the video.
Whatever is bothering her the visible manifestations are episodic and she recovers quickly from them. She can also do appearances but obviously not in a free wheeling manner. Whatever can be controlled they do their best to control. I guess it’s possible to continue to campaign in this manner but it’s going to be also somewhat episodic in nature.