Assalamu Alaikum sister,
I have a friend who wants to get married to someone whom they are related to. The man's mother and her grandmother are sisters. Now the mother of the girl is saying that ‘you two are related so you can’t marry each other’. Is it permissible for them to marry?
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
The man and woman here are cousins. Cousins can marry each other in Islam.
Prophet (s.a.w)’s daughter, Fatima (R.a), also married her cousin Ali (R.a). It is permissible for them to marry each other.
Only Allah knows best
Written by Alimah Sumeyye Sofu
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 al Hidaya 1/451 Kahraman / Surah Nisa 23