Is it considered disbelief (kufr) if a mother says, while angry, "You make one disbelieve against their will," or "I don't want to pray because of you; I want to disbelieve," and what are the resulting rulings concerning her prayer, fasting, and marriage?

Uttering words that suggest a devaluation of religion is dangerous, and the mother should be advised to be cautious of them. For instance, the phrase "you make one disbelieve" is not disbelief in itself, but rather an indication that certain actions might lead to disbelief. Similarly, the phrase "I want to disbelieve" is not disbelief unless one intends by it to reject Islam or resolves to disbelieve.

Her prayers and fasting are evidence that she does not intend to abandon Islam, and the default is that she remains Muslim. Even if she disbelieved and then prayed, she would be judged as a Muslim.

The mother should be advised gently and kindly on the necessity of guarding her tongue and avoiding anger. The questioner should also avoid provoking her mother and resist the whispers (waswas) related to purity by ignoring them and seeking refuge in Allah.