Is it permissible for a mother to take her working daughter's entire salary to give it to her son, and is it permissible for the daughter to conceal part of her salary without her mother's knowledge?

A woman has her independent financial responsibility, and her money is exclusively hers. It is not permissible for anyone to take from it except with her willing consent, due to the Almighty's saying: "And give the women [called dower] their due, a gift. But if they should be willing to give up to you anything of it, then take it in satisfaction and ease." And due to the Prophet's (peace be upon him) saying: "The property of a Muslim is not lawful except with his willing consent." The Sacred Law has made an exception for the father, and some scholars have included the mother in taking from the child's money under certain conditions, such as not causing hardship to the child and not taking from one child's money to give to another child. Based on this, it is not permissible for your mother to take your money against your will to give it to your brother, and there is no blame upon you for keeping a portion of your salary and concealing it from her.