'Abdullah bin Mas'ud said, about the grandmother along with her daughter:
"The Messenger of Allah(S.A.W) gave the first grandmother, along with her son, a sixth for them to consume while her son was living." (FR)
English reference (FR): Vol. 4, Book 3, Hadith 2101 (FR)
Arabic reference (FR): Book 29, Hadith 2248 (FR)