The ruling on marrying a woman who was breastfed with one's sister

Question:
May Allah reward you with good and do you well. From Jarash in the Hashemite Kingdom of Jordan, a message was sent by the listener Rida Ahmad Bayumi, who asks and says: I am a young man who wants to marry a young woman who was breastfed with my sister. Is it permissible for me to marry her or not?

Answer:
If your sister was breastfed by her mother and became her sister through breastfeeding, then this does not affect your marriage to her; because the ruling of breastfeeding only extends to your sister who was breastfed, whereas the ruling of breastfeeding does not extend to you. However, if it is the reverse, and she was breastfed by your father’s wife, then she is not permissible for you; because she becomes your sister through breastfeeding. If she was breastfed by your mother, or by your father’s wife, or by one of your breastfeeding mahrams, with complete breastfeeding within the two-year period, then she becomes forbidden to you through breastfeeding, just as if she had been breastfed by your sister, or if she had been breastfed by your wife, or if she had been breastfed by your daughter. Yes.