I want my girlfriend to complain less about work
Why is your girlfriend complaining about her work?
It just sucks, all of her coworkers and her boss are rude and they don't do their work.
It can be hard to listen to complaining all the time but as her partner it is important for you to listen. Maybe help her find another job where she will be happier.
I'll give her a credit for sticking with her place of work for so long.
Try to listen to your girlfriend and help her express her emotions about her work. Find out if she wants to change jobs or is just getting work drama off of her chest. Either way, support her and show her you care about her problems.