One of the advantages a sister has when arguing with a brother is that she is under no obligation to be tactful. If she wishes to tell him that he is an idiot and ought to have his head examined, she can do so and, going further, can add that it is a thousand pities that no-one ever thought of smothering him with a pillow in his formative years.
The passage highlights a sister's unique position in conflicts with her brother, emphasizing her freedom to speak her mind without concern for politeness. Unlike others who might choose their words carefully, she can express her frustration openly, calling him harsh names if she sees fit. This candidness suggests a dynamic where the sister feels comfortable being blunt and honest.
Additionally, the exaggeration of wishing harm upon him as a joke illustrates the playful nature of their relationship. It showcases the sibling bond where affection can be mingled with teasing, hinting that such arguments, while sharp, are fundamentally rooted in familiarity and love. The humor in the extreme nature of her comments suggests a deeper connection beneath the surface of their bickering.
