What is the ruling regarding the mother's infrequent prayer and shortcomings in the last period of her life, knowing that she was ill and believed to have been afflicted by possession (mass), and she resisted the illness and possession throughout her life, in addition to her good conduct and her daughter's two dreams about her?

May your mother be granted mercy and accepted among the martyrs, based on the hadith: "The martyrs are five: the one who dies of plague, the one who dies of a stomach ailment, the drowned, the one who dies under a collapsing building, and the martyr in the way of Allah." The "one who dies of a stomach ailment" is interpreted as anyone who dies from an abdominal disease. As for prayer, the sick person must perform it according to their ability; if they are unable, the obligation is lifted from them. One whose mind is gone due to illness is not accountable and does not need to make up missed prayers. Based on what you mentioned about her faith and good deeds, we hope for her success and salvation. It is recommended to supplicate for her and give charity on her behalf.