Is it permissible to save for a second child without doing so for the first, relying on the first child's inheritance to cover their education expenses, in order to ensure that both of them attend good schools as much as possible?

Justice must be observed among children in gifts and donations, whereas maintenance (housing, clothing, food, education) is according to each child's need. If the first child is self-sufficient and does not need maintenance for studying, while the second child needs it, there is no harm in saving for him; because maintenance for the rich differs from that for the poor. This saved money remains the father's property, and he spends from it on the child when the anticipated need arises. If the child becomes self-sufficient before that, or the father dies, the money returns to the estate and is divided as inheritance. Justice in giving and gifting is specific to the father's money. As for the mother, she may give her child from her private money whatever she wishes, even secretly, to avoid a bad relationship between the siblings. Attention must be paid to seeking lawful investments and avoiding usury.