Excerpt from Fatāwā Amaanpuri by Shaykh Ghulām Mustafa Zaheer Amaanpuri
❖ Question:
A woman breastfed a non-Muslim girl who later accepted Islam. Can the woman’s brother marry that girl?
❖ Answer:
Their marriage is not permissible.
The woman’s brother becomes the foster maternal uncle (raḍāʿī māmūn) of the girl, and she becomes his foster niece (raḍāʿī bhānajī).
Just as marriage between a biological maternal uncle and niece is forbidden, marriage between a foster maternal uncle and niece is also prohibited.
✿ Qur’anic Evidence:
﴿وَبَنَاتُ الْأُخْتِ﴾
“And (forbidden to you in marriage are) the daughters of your sisters.”
📖 Surah an-Nisā’ (4:23)
This includes both biological and foster (raḍāʿī) nieces, as the relationships prohibited by birth are also prohibited through breastfeeding.
✅ Conclusion:
Therefore, it is haram (forbidden) for the woman’s brother to marry the girl she breastfed — even if the girl later embraced Islam — because they are foster relatives through raḍāʿah.
