Marrying a maternal cousin who was previously married to her brother-in-law

Q: I want to marry my maternal cousin, but my mother refuses because she fears that the girl might be unlawful for me to marry. The mother said that when her husband died, she was pregnant and her family was living in a far-off district. Since she was epileptic and her married sister was living nearby, she had to move to her sister's house because of her illness and the long distance to her family. The mother further explained that her brother-in-law had sexual intercourse with her when her sister was out of the house and she was suffering from one of her fits. He did that two times after which she asked the help of some kind neighbors and sent for her father to come and take her from her sister's house. The mother now fears that the girl might be unlawful for her son to marry, because of the illegal sexual intercourse committed by her brother-in-law? Does this intercourse prevent me from marrying this girl, bearing in mind that we are not related through suckling and there is no other impediment except what is feared by my mother?

A: If the reality is as you mentioned, that you are not related to each other through suckling and there is no impediment to your marriage to her except what your mother has mentioned and feared might represent an impediment to marriage, then you are permitted to marry your maternal cousin, the daughter of the man who committed what your mother mentioned. This sexual intercourse is not an impediment to marriage. (Part No. 18; Page No. 352) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.