If one doubts that he was breastfed by a woman five times, is he permitted to marry her daughter?

Question:
He sent a question saying: I have proposed to my cousin’s daughter, who was breastfed along with her older brother. However, her mother insists that I did not breastfeed much, meaning, in other words, that I did not exceed five feedings. She is willing to swear to the truth of this statement, but I doubt the accuracy of her words. Knowing that I have already asked about this matter and received differing answers, some permitting it and others forbidding it, what is the opinion of the religion? May Allah reward you with all good.

Answer:
The decisive solution in this matter is that breastfeeding must be five times within the first two years. If it is established that you were breastfed five times within the first two years by this woman, then it is not permissible for you to marry any of her daughters or the daughters of her husband, even if they are not from the breastfeeding mother who provided the milk. However, if it is not established that you were breastfed five times, the default is permissibility and the absence of prohibition, because, according to the stronger position, only five known feedings within the first two years render marriage forbidden. If you avoid her as a precaution and to steer clear of doubtful matters, that is better for you.
The Prophet (peace and blessings be upon him) said: . And the Prophet (peace and blessings be upon him) said: “Whoever avoids doubtful matters has protected his religion and his honor.” So if you avoid her as a precaution and to steer clear of doubtful matters, that is better. And women are many, praise be to Allah. But prohibition does not apply to you except by what we mentioned: the establishment of five feedings within the first two years from her mother or from her father’s wife. Yes. May Allah reward you with good and give you a good festival.