Is it permissible for the mother to approve of her son's disposal of his sisters' money and their house without their consent, especially after he had previously refused to host them in his house, and is the money set aside for Hajj a promise that must be fulfilled?

If children reach maturity, no one has guardianship over their wealth, and they may dispose of it as they wish, based on the Almighty's saying: "And test the orphans until they reach the age of marriage. Then if you perceive in them sound judgment, release their property to them." The children's money and salaries are their own property, and their sustenance is upon themselves as long as their salary suffices them. The mother is not allowed to prevent them from disposing of their money or to take from it for herself without need, nor to give the daughter's money to her son, based on the Almighty's saying: "Do not consume your property among yourselves wrongfully, except for a trade by mutual consent." The brother has no guardianship over his siblings' money, and he is not entitled to dispose of shared money without everyone's permission, except in cases of necessity to repair a common property, such as a dilapidated house, in which case everyone is compelled to participate, based on the Prophet's (peace be upon him) saying: "There shall be no harm nor reciprocating harm." It is advisable to agree with the mother on a common amount for expenditure, and to place the rest of the money in an Islamic bank so that the mother can be assured of its growth and preservation.