Is the father obligated to inform his deceased brother's daughters about the financial grant allocated to them by the state, and is it permissible for him to continue spending on them from the remaining portion of this grant, knowing that he is well-off?

The uncle must manage the funds of the grant allocated to the orphaned girls according to the stipulated conditions or custom. If he violates these, he guarantees the money. He is obliged to spend on them in a customary manner and to safeguard their funds until they reach maturity, at which point he must hand over what remains to them. He is not permitted to manage their funds after they reach maturity except with their permission, unless the granting entity specified the avenues of expenditure after their maturity. Before they reach maturity, he should spend on them in a customary manner without being obligated to inform them of the details of the grant.