Is it permissible or forbidden for a grandmother to allocate a portion of land to her grandchildren whose father has passed away, after she had gifted other portions to her daughters?

Favoring some children with a gift without a legitimate reason is impermissible. If the donor dies before revoking the gift, then it is established for the donee according to the majority of scholars. However, if the grandmother gave her daughters a portion of her land and the gift was not taken possession of during her lifetime, then it becomes void and returns to the estate. If the daughters took possession of the gift during her lifetime and disposed of it, then it is a valid gift specifically for them, and the husbands' threats of divorce do not affect its validity. What the uncle did by writing a portion of the land to himself or to you does not entail anything, and he does not own the land thereby; because the mother's consent is necessary if she was alive, and after her death, the property belongs to all heirs, and he is not permitted to dispose of it without their consent.