The amount of breastfeeding that results in prohibition

Question:
I have a cousin’s daughter whom I wish to marry. She was breastfed by more of my maternal uncles, not by my paternal uncles. Please note that the milk belonged to a man whom my mother had previously divorced. My mother does not know how many times she breastfed her: three times, two times, or more. So I do not know. What is your opinion, Your Eminence, in this matter?

Answer:
Praise be to Allah, and may Allah send prayers and peace upon the Messenger of Allah, upon his family and his Companions, and upon those who follow his guidance. As for what follows:
The breastfeeding that results in prohibition must be five breastfeedings, or more, within the two-year period. This is based on what is established from ‘A’ishah (may Allah be pleased with her) in Sahih Muslim, where she said: “It was among what was revealed in the Qur’an that ten known breastfeedings result in prohibition, then this was abrogated by five known breastfeedings. The Prophet (peace and blessings be upon him) passed away while this was still being recited in the Qur’an.” In a narration by al-Tirmidhi, it says: “And the matter remains as it was.”
In her hadith as well (may Allah be pleased with her), the Prophet (peace and blessings be upon him) said to Sahlah bint Sahil: “Breastfeed Salim five times, and you will be prohibited to him.” Therefore, five breastfeedings are required. If the wet nurse does not know whether she breastfed him once, twice, three times, or more, then this breastfeeding is not considered valid. It does not make the infant her son, nor a brother to her children, nor a son to her husband who provided the milk, unless the breastfeeding amounts to five or more, and unless the nursing child is within the two-year period. This is based on his saying (peace and blessings be upon him): .