Making money is a good reason.
Not if you care more about the state you are governing, which Sarah clearly did, and that is why she resigned. Context, context, context. If sarah had a history of quitting jobs then I would be very suspect of her resignation, but she does not, so that resignation was unique with unique conditions. Her past shows that she has been a loyal and very hardworking servant, and she continued with that by resigning in light of heavy burdens that were keeping her from doing her job.