Does the utterance of the Shahada by the grandfather's wife upon her death signify God's contentment with her and His forgiveness of her, taking into consideration the great injustices she inflicted upon others, especially the questioner's mother, and the raqi's testimony of the presence of a sorcery linked to her, in addition to her mother's death which was preceded by strange circumstances?

If your grandmother's wife uttered the Shahada at the time of death, this is a sign of goodness and entry into Paradise, according to the Prophet, peace and blessings be upon him: "He whose last words are 'There is no god but Allah' will enter Paradise." She may also have had good deeds that expiated sins, or calamities that atoned for them. Her harming your mother, uncles, and aunts – if that is true – does not prevent her from having a good end. The default is the acquittal of her responsibility for what was attributed to her regarding sorcery, and it is obligatory to think well of a Muslim. It is not permissible to attribute that to her merely based on the words of the exorcist or the jinn, because the words of the jinn are not reliable. There is no religious basis that every oppressor is punished by Allah before his death with a penalty or a bad end.