Rowena is actually a walking parody of something that happened in real life. For relevance: https://en.wikipedia.org/wiki/Company_scrip
Workers were more or less owned by the Company, just like Rowena's workers are. They are indebted and contracted to her. They are paid only in scrip which can only be used in her store fronts. Often these workers IRL (and just like poor Gerolt) only get deeper in debt no matter how much they work, thus keeping them under the company's (or Rowena's) thumb. Meanwhile, she rakes in all of the actual monetary profit of their work and they don't really see any of it, same as the IRL companies did.
There is a pretty famous song about all this by the name "Sixteen Tons." It's pretty good.