What is the ruling on bequeathing half of the house to the sisters, and is it permissible to execute a will to buy a plot of land for the eldest sister from the remaining money, and what should be done regarding the will for an ongoing charity (Sadaqah Jariyah) from the house's rent?

A will in favor of an heir is not permissible unless approved by the remaining adult and sane heirs. If they approve it, it becomes binding. This is the view of the majority of scholars. Some scholars hold the view that such a will is invalid even if the heirs approve it, unless it is a new gift. A Waqf (endowment) made during a death illness, or one that is contingent upon death, has the ruling of a will; thus, it may not exceed one-third [of the estate] unless approved by the heirs. It is recommended to establish a Waqf for the deceased mother. There is no obligation to inform the siblings about the mother's impermissible will to register half the house to the daughters, unless there is knowledge of their generosity and their willingness to relinquish their right with good grace. Charity given on behalf of the deceased benefits them and reaches them, by the consensus of Muslims.