What is the ruling on a wife refusing to raise her husband's brother's children, and is she sinful for that, and is she obligated to do so in obedience to her husband?

There is no blame on the paternal uncle's wife for refusing to host her husband's children in her home, and she is not obliged to obey him in this matter. She has the right to a private residence. She is not considered disobedient (nashiz) if she leaves the house due to the children's residence there. The husband should not threaten his wife with marrying another to force her agreement, as this is poor companionship, and Allah Almighty has commanded kindness. He is not permitted to abandon her or refrain from speaking with her for this reason, as abandonment is only permissible when she is disobedient and only in bed. The default is the wife's innocence from the suspicion that she performed magic, and it is not permissible to harbor ill suspicions without proof. If he fears magic, the treatment is ruqyah (Islamic exorcism). After the mother remarries, the custody of the children transfers to the one most deserving according to the jurisprudential order.