What is the religious ruling on refusing to help one's mother when angry and when a son rages at his uncooperative brother, and what is the son's duty towards his mother in this situation?

May Allah reward you for helping your mother, for this is an act of righteousness, and its consequences are good in this world and the Hereafter. Do not invalidate your good deeds by reminding her of them or causing her harm. Do not be concerned with your brother's shortcomings, and advise him with gentleness and kindness. Avoid anger, for it brings no good. Strive against your ego and suppress your rage. Do not refuse your mother's request for help under the pretext that your brother does not fulfill her requests, for "no bearer of burdens will bear the burden of another," and everyone has their own reward and burden.