Also an idea: maybe she is fast because she has rest and downtime. We are more productive when we are not working all the time and have rest.
It baffles me because my initial reaction to someone like that is to think they’re not good. But she’s really good. She’s able to pick things up on the job fast and is extremely focused on her work. I OTOH always need to use my personal time to learn things and have trouble focusing, despite being a tech enthusiast.
But, I think that since she is "extermly focused on job" she probably likes (or at least does not hate) the job itself - not pop version of what programer should like or random messing with gadgets, but the job itself. Many people are like that - they are able to like many different things, so they like what they are doing now.