All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
In fact, one is not held accountable for the passing feelings and thoughts that occur in one's mind and that one has no control over. Allaah, The Exalted, says (what means): {… And there is no blame upon you for that in which you have erred but [only for] what your hearts intended. And ever is Allaah Forgiving and Merciful.} [Quran 33:5]
Moreover, Abu Hurayrah related that the Prophet, sallallaahu ‘alayhi wa sallam, said: “Allaah has forgiven my Ummah (nation) whatever evil thought that occurs to their minds, as long as such thoughts are not put into action or uttered.” [Al-Bukhari and Muslim]
However, there is no doubt that rejoicing at the death of one’s mother is a blameworthy feeling. How could one rejoice at the death of the woman who has exerted endless efforts in tending to him/her as a child and endured much in pregnancy, nursing, and taking care of him/her? Allaah, The Exalted, says (what means):
· {And We have enjoined upon man [care] for his parents. His mother carried him, [increasing her] in weakness upon weakness, and his weaning is in two years. Be grateful to Me and to your parents; to Me is the [final] destination.} [Quran 31:14]
· {And We have enjoined upon man, to his parents, good treatment. His mother carried him with hardship and gave birth to him with hardship, and his gestation and weaning [period] is thirty months…} [Quran 46:15]
Finally, we advise you to strive in being dutiful to your mother after her death. Fatwa 83233 highlights how children can be dutiful towards their parents after their death.
Allaah Knows best.