I'm going to tell my girlfriend she should quit her main job.
Why do you want her to quit the job?
She works too much and doesn't have enough time to spend with me.
It does feel bad when your girlfriend can't spend time with you but you shouldn't try to control her. She needs to work to maintain herself.
I think her job is too demanding on her.
If you think she'd be happier working less, talk to her about it. But trying to control her because you want her around more is wrong, and it will only make her mad.