Don’t Promotions Fall Out of the Sky?
The self-entitlement in the OP’s girlfriend reaches unfathomable heights. “I cannot believe anyone would make somebody work for almost a year to get a promotion.” Those are her words, according to the OP. Almost a year. Most people have to slave for years and years before their bosses even consider promoting them!
However, if you want to take on more responsibilities without pay, they’d be more than happy to take you up on your offer, but that’s beside the point. Since this young woman is trying to make a living on her own, we can let her ignorance slide. She’s just learning, y’all.