Musannaf Ibn Abi Shayba 26:228

Ibn Fudayl narrated to us, from Bassam, from Fudayl, who said: Ibrahim said regarding a woman who left behind her mother, her sister from her father and mother, her brother from her father, and her grandfather: Zayd judged regarding it that the mother has one-sixth, and the grandfather has two-fifths of what remains, and the sister has three-fifths of what remains. He returned the brother to his brother, and he did not inherit anything. Abdullah judged regarding it that the sister has three shares, the mother has one share, and the grandfather has one share. Ali judged regarding it that the sister from the father has three shares, the mother has one share, and two shares remain; the grandfather has one share and the brother has one share. Abu Bakr said: This, according to the opinion of Ali and Zayd, is out of six shares, and according to the opinion of Abdullah, it is out of five.