Is it obligatory to dispose of the money inherited by a patient with Alzheimer's from her brother, knowing that a large portion of it came from usurious transactions? What is the ruling on the lawful portion of this money? Is it permissible for the son to use this money for charitable acts on behalf of his mother?

It is not permissible to dispose of the sick mother's money except for what is in her best interest, developing it, and paying its zakat. It is not permissible to perform charitable acts with her money unless she commands it while she is fully conscious and within the limits of one-third (of her estate). The previous statements made by your mother and uncle about doing good deeds with money are not considered a legal will unless there is clear evidence. Reward or sin is established by sincere intention and firm resolve. The mother's money must be kept, and if she regains consciousness, she should dispose of the usurious gains by spending them on the interests of Muslims. If she passes away, the illicit money must be disposed of and the obligatory rights fulfilled before dividing the inheritance. It is advisable to seek assistance from the Sharia court in these matters.