Anyway, I'm mainly here to point out the obvious that the girl is using a single base, not double. Or are you saying there is something special or tricky about the pedal itself? Gawd please don't reveal you are an expert on music minutia as well...
I am far from expert on anything of course, but i have been playing guitar, banjo, bass, and the dobro guitar off and on for over 20 years, so i do know some random stuff. While she does play with a single bass pedal for most of the song, the end where it picks up she's using a double bass pedal, which is shown in the lower corner. 2:45 you can clearly see her going. For the rest of the song she's playing single triplets, which is 3 notes instead of the single. Bass pedals have an adjustable spring in them, and they rebound very well, much like bouncing a basketball. A very small movement with the foot makes a huge movement in the pedal, which also helps for speed. She's playing barefoot, and will easily feel the sweet spot, and with practice it becomes similar to bouncing a ball with the rebound.
The video in question.....
It's a repost of mine, but this girl still leaves me awed...
Now, for zep being a cover band. While yes, they were/are hugely popular, that doesnt make them songwriters at all. They picked cool songs, and played them, almost note for note, and put their own names on it. That's flat out stealing. Some songs were blues numbers that weren't in the white conciousness at the time, but many were simply more obscure songs in different genres. On a side note, the blues songs they stole they totally ruined, which takes a special kind of suckiness
And stairway