Her co-workers seems fine and doesn't seem burdened with work as much as her.
The workload on her is just too much should have told her boss or just look for another job.
@versub I think you missing a huge important point, this is japan the eastern world not western world where you can kinda hop jobs, there (per manga logic in other manga) asking for less heavy load = lazy ass, looking for another job, they will be asking why you left your old job if was a stable work, the looking for new knowledge would work that much, of course all of this from the logic of other mangas