How can a woman prepare for death, which she now perceives at every moment, and ready herself with charity and good deeds, while also being anxious about the fate of her children after her passing? Should she write a will to designate who will raise them, and a will for them to fear Allah and prostrate frequently when they grow up? And should she advise her husband not to remarry after her death out of compassion for the children?

Regarding your compassion and tenderness towards your children and your fear for them after death, this is a natural emotion. Allah Almighty has enjoined justice towards orphans. If you leave a will for your children enjoining piety and reconciliation, this is in line with the guidance of the righteous predecessors.

As for a will concerning their companionship, there is no harm in it, but guardianship and custody are matters for the Lawgiver. However, a husband's will enjoining his wife not to remarry after him is not permissible, you have no right to it, and no legitimate benefit is achieved by it.