What happens to her if her performance is improved?

That entirely depends on the company she works for, and her own disposition.

Quite likely she will be punished for it, directly or indirectly. This is why it’s bad to be an employee. If you earn a living by knitting scarves in your house and work out a way to make them faster or better, or both, you’ll make more money or have more free time. If you knit scarves for a salary you’ll probably suffer for doing it faster or better.

> Quite likely she will be punished for it, directly or indirectly.

Not at most modern companies in the real world.

Jobs have already been so hyper-specialized that you have minimal staff "managing" large portions of the company, amortized over a large number of locations / amount of business.

Consequently, if a job task is taken off their plate, there are innumerable additional tasks to backfill the free time.

And critically, tasks that are probably more intellectually fulfilling than the lowest-hanging-fruit rote tasks that are automated.