Is it permissible to marry the daughter of my maternal aunt if there is doubt about the existence of suckling between us, given that my paternal grandmother breastfed me in my childhood, and she was also the maternal grandmother of my maternal aunt's daughter at the same time?

If a woman breastfeeds a child under the age of two, the child becomes her own. However, scholars differ on the number of feedings required for the prohibition to be established. The Hanafis, Malikis, and Hanbalis (in one narration) hold that prohibition is established with a single feeding. The Shafi'is and the predominant view among the Hanbalis stipulate five feedings, and this is the fatwa we follow. If it is confirmed that you were breastfed five times by your grandmother, then all your maternal aunts' daughters are forbidden to you. However, if you were breastfed fewer than five times, or if there is doubt about the number or about the breastfeeding having occurred at all, then the prohibition is not established. It is more prudent to refrain from marrying this girl if the prohibition is not established with certainty, due due to the saying of the Prophet, peace and blessings be upon him: "How can it be, when it has been said?"