Should the father's deceased estate and the rent from his leased house be spent on the minor children according to their needs, or should it be spent on all family members without distinction?

Minor orphans are to be provided for from their own funds, and what is best for them must be observed in interaction and other matters, as stated by Allah Almighty: "And do not approach the orphan's property except in a way that is best." It is preferable to interact with them if the intention is reform, as stated by Allah Almighty: "And they ask you about orphans. Say, 'Improvement for them is best.' And if you mix with them, they are your brothers." If household expenses are normal for necessary needs, there is no harm in mixing the funds of minors with those of adults. As for other expenses like school fees, it is not permissible to spend from the minors' funds on them unless they have similar needs.