Praise be to Allaah.
The mahram relationship
through breastfeeding cannot be proven unless there were five definite
breastfeedings, because of the report narrated by Muslim (1452) from
‘Aa’ishah (may Allaah be pleased with her) who said: Among the things that
were revealed of the Qur’aan was that ten definite breastfeedings make a
person a mahram, then that was abrogated and replaced with five definite
If there is doubt as to
whether breastfeeding took place, or about the number of breastfeedings,
then the mahram relationship cannot be proven.
Ibn Qudaamah (may Allaah
have mercy on him) said in al-Mughni (8/138): If there is doubt as to
whether breastfeeding took place, or about the number of breastfeedings
which make one a mahram, whether it was complete or not, then the mahram
relationship cannot be proven, because the basic principle is that it does
not exist, and what is certain cannot be altered because of doubt. End
Based on this, so long as
you are not certain about the number of breastfeedings from the grandmother
of the girl whom you want to marry, then the mahram relationship cannot be
proven in the event of doubt, and the basic principle is that this girl is
permissible for you.
But if it is proven that
you were breastfed (by the grandmother), then (the girl’s mother) is your
sister, and you are a maternal uncle of this girl through breastfeeding, so
she is not permissible for you.
For the sister who was
breastfed by your mother, if she was breastfed five times, then she is your
sister and the sister of all your brothers, and her daughters are mahrams
for you, because you are their maternal uncle through breastfeeding.
And Allaah knows best.