What is the ruling of Islamic law regarding the actions of a mother who took her orphaned daughter's pension and deposited money, and saved nothing for her, and is the noble verse: (And give orphans their property, and do not substitute the bad for the good, and do not consume their properties into your own. Indeed, that is a great sin), relevant to this case?

The pension belongs to the orphan, and their guardian must manage it responsibly. It is permissible to spend from it on the orphan in a reasonable manner and to invest any surplus. It is also permissible to mix the guardian's money with the orphan's money to avoid hardship. A poor guardian may partake from the orphan's money in a reasonable manner. When the orphan reaches maturity and is of sound judgment, their money must be handed over to them. It is forbidden to take an orphan's money unjustly, as this is among the gravest sins. It is permissible for a mother to take from her son's money when in need, provided it does not harm him, or cause him injustice, or is taken for another child. If an orphaned girl reaches maturity, she must manage her own money.