Is a mother sinful if she prefers her less fortunate children in inheritance with financial gifts, while her wealthier children argue with her that this is their legitimate right?

Parents must be just among their children in giving, and the mother in this regard is like the father. It is not permissible to prefer some children in giving merely because they are less fortunate than others, unless with the consent of the others. If a genuine need arises for some children, some scholars have permitted specialization and preference at that time, while others have prohibited it. The mother must strive for justice among her children. Anything she has specifically given to some children without justification, she must reclaim it or give the equivalent to the rest, unless they consent and forgive.