What is the ruling if the adult wife's grandmother, sister, brother's wife, brother's daughter, or sister's daughter breastfeeds the minor girl with the adult wife's milk?
General Chapter
Al-Mughni
Book of Fosterage (Breastfeeding)
Primary text
The ruling is the same if the adult wife's grandmother breastfeeds the minor girl, as this results in the adult wife becoming the aunt (paternal or maternal) of the minor girl, and combining such relatives in marriage is forbidden. Likewise, if the adult wife's sister or brother's wife breastfeeds the minor girl, it results in the minor girl becoming the niece (daughter of the sister) or nephew (daughter of the brother) of the adult wife. Similarly, if the minor girl is breastfed by the adult wife's brother's daughter or sister's daughter, the same consequences apply.
Supporting text
None of these scenarios result in permanent prohibition; rather, they result in prohibitions against combining two women in marriage, unless the adult wife's daughter breastfed the minor girl when consummation had occurred with the mother.