Why doesn't she quit? Then someone else who wants her job can have it and she can find other work that compensates her properly. Who would work somewhere unhappily for 20 years?
Mine doesn't make a ton either especially in North Carolina a non unionized state. But she gets paid well for working 8.5 months per year. Summers off is an incredible advantage, huge amounts of time at each and every Holiday, she can retire at 54 (30 years) and gets 80% of her pay for the rest of her life.