Why does Slipslop get fired from her job by Mrs. Booby?

Lady Booby orders Slipslop to have the steward pay Joseph his wages and send him away. Slipslop opines that if she had known how Lady Booby would react, she would never have reported Joseph’s behavior. After sending Slipslop out of the room and then calling her back again, Lady Booby censures her for impertinence, whereupon Slipslop says darkly, “I know what I know.” Lady Booby promptly fires her, and Slipslop departs the room, slamming the door behind her. Lady Booby then begins to worry about her reputation, which she perceives is in the hands of Slipslop, who no longer has any incentive to be discreet; after a time she calls Slipslop back again and reinstates her.