Huzayl (may Allah have mercy on him) said that Abdullah (may Allah be pleased with him) said, regarding a woman who left behind her husband, her mother, her full brothers and her maternal half-brothers: For the husband is a half, for the mother a sixth, and for the maternal half-brothers a third, completing the shares. And he did not assign any share to her full brothers.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12478