The schools concur that the female relatives with whom marriage is prohibited are of seven kinds:
1. Mother, which includes paternal and maternal grandmothers.
2. Daughters, which includes granddaughters how low so ever.
3. Sisters, both full and half.
4. Paternal aunts, which includes fathers' and grandfathers' paternal aunts.
5. Maternal aunts, which includes fathers' and grandfathers' maternal aunts.
6. Brother's daughters how low so ever.
7. Sister's daughters how low so ever.
The above prohibition has, its origin in the following verse of the Qur'an:
حُرِّمَتْ عَلَيْكُمْ أُمَّهَاتُكُمْ وَبَنَاتُكُمْ وَأَخَوَاتُكُمْ وَعَمَّاتُكُمْ وَخَالَاتُكُمْ وَبَنَاتُ الْأَخِ وَبَنَاتُ الْأُخْتِ
Forbidden to you are your mothers and your daughters and your sisters and your paternal aunts and your maternal aunts and brother's daughters and sister's daughters... (4:23)