What should the questioner do about his mother who dislikes and hates the niqab, and practices fortune-telling with cards? Should he inform his father about this, fearing that problems might arise between them or that his mother might get angry with him? Will Allah forgive her while she is in this state? And what should he do with his brother who has completely abandoned prayer after he used to pray, knowing that one who abandons prayer is a disbeliever?

The possibility of Allah forgiving your mother, who insists on divination, depends on the type of divination. If it is polytheism (shirk (definition)) that takes one out of the fold of Islam by claiming knowledge of the unseen (ghayb), then Allah does not forgive shirk. However, if it is a sin less than disbelief (kufr), then it is under Allah's will. Scholars have differed on the ruling regarding a soothsayer (kahin); whether they commit disbelief or should be disciplined. Some believe that a soothsayer commits disbelief by claiming knowledge of the unseen because it contradicts the text of the Quran. You must strive to advise your mother and inform your father to stop her from divination, and continue advising your brother regarding prayer and supplicating for his guidance.