Why does the employer trick the governess?

The employer tricks the governess to manipulate her into believing that she is solely responsible for the well-being of the children, thereby increasing her loyalty and commitment to the household. This deception serves to isolate her and maintain control, ensuring that she remains compliant and dedicated to the employer's interests. Ultimately, it reflects the power dynamics at play, showcasing the employer's desire to maintain authority over the governess and the situation.