The daughter honored her mother's explicit request for a small, quiet dinner. The brother's actions were a direct contradiction of their mother's stated desires, causing her unnecessary stress and discomfort. The daughter should not be blamed for respecting her mother's wishes.
The brother's intentions were to celebrate their mother's milestone birthday in a grand fashion, believing she secretly desired a larger celebration. The daughter's rigid adherence to the initial plan, despite the brother's efforts, made him look bad in front of the family and caused unnecessary division. She should have been more flexible and supportive of the brother's initiative.
The brother unilaterally decided to throw a large party, disregarding the mother's expressed wish for a quiet dinner and the sister's agreement to honor that wish. While his intentions may have been good, his actions were disrespectful and caused the mother stress. The sister is not at fault for adhering to the original plan and respecting their mother's desires. It is important to listen to and respect the wishes of the person being celebrated, rather than imposing one's own preferences.