Is it permissible for a wife to conceal part of her husband's invested money to buy an apartment in the name of her children, claiming it is for her mother and sisters, while the husband knows that the money is for his children?

It is forbidden for a wife to buy an apartment for her mother with her husband's money without his knowledge and consent, because this is considered treachery and an unlawful consumption of wealth, even if it is for the purpose of showing kindness. The wife is entrusted with her husband's money, and she is not permitted to dispose of it except with his permission, especially in matters of high value, based on the Prophet's (peace be upon him) saying: "It is not permissible for a woman to give a gift except with her husband's permission." An exception to this is a small, customary amount that is usually overlooked and for which there was general permission, in which case the wife would receive half the reward. The fact that the apartment will be registered in the children's names does not change the impermissibility of the act, as the apartment belongs to the father. The wife must fear Allah and inform her husband of all the profits from his business and return what she took without his knowledge.