What is the ruling of Islamic law regarding a mother who prevents her daughter from receiving her full share of her father's inheritance, such as giving her half a qirat of land instead of a full qirat, and threatens her with anger and boycott if she does not agree, knowing that the daughter is not in financial need and her husband is well-off?

If the mother is not in need, the daughter is not obligated to leave her anything from her father's inheritance. However, if she is in need, the daughter is obliged to provide for her. It is better for the daughter to leave all of it to her mother and even increase it if that pleases her, and to strive to remove any resentment her mother may harbor; because showing kindness and benevolence to one's mother brings Allah's pleasure. Allah Almighty says: "And your Lord has decreed that you worship none but Him. And to parents, show goodness." [Al-Isra: 23]. The Prophet, peace and blessings be upon him, emphasized the mother three times before the father. In summary: it is advised to treat the mother with kindness, gentleness, and tenderness.