It depends on the kind of seizure they have.
Of course it does. Name one type of seizure which causes a head jerk as she exhibited. And which doesn't destabilize an individual to the point of losing their balance and falling...
Are you talking about the most recent 'medical emergency'? I don't know if that was a seizure or not, she certainly was not "with it", was stiff legged, couldn't tell if she was shaking/seizing or in the process of losing consciousness and 'wobbled' prior to them dragging her into the car. She was most def unconscious when they put her in the car.
The video with the reporters? I didn't think that was a seizure as much as a goofy/jokey reaction to the people bombarding her with questions. I've watched it several times, though, and her eyes are very strange in it but I'm not convinced that was anything more than her just joking around. Could that have been some type of mini-seizure? Don't know, dont' think so.
As for seizures, there are types that occur and a person will not fall down from them. They're called peti mal or absence seizures.