Surah An-Nisa, verse 176

يَسْتَفْتُونَكَ قُلِ ٱللَّهُ يُفْتِيكُمْ فِى ٱلْكَلَـٰلَةِ ۚ إِنِ ٱمْرُؤٌا۟ هَلَكَ لَيْسَ لَهُۥ وَلَدٌ وَلَهُۥٓ أُخْتٌ فَلَهَا نِصْفُ مَا تَرَكَ ۚ وَهُوَ يَرِثُهَآ إِن لَّمْ يَكُن لَّهَا وَلَدٌ ۚ فَإِن كَانَتَا ٱثْنَتَيْنِ فَلَهُمَا ٱلثُّلُثَانِ مِمَّا تَرَكَ ۚ وَإِن كَانُوٓا۟ إِخْوَةً رِّجَالًا وَنِسَآءً فَلِلذَّكَرِ مِثْلُ حَظِّ ٱلْأُنثَيَيْنِ ۗ يُبَيِّنُ ٱللَّهُ لَكُمْ أَن تَضِلُّوا۟ ۗ وَٱللَّهُ بِكُلِّ شَىْءٍ عَلِيمٌۢ ﴿١٧٦﴾

4:176 They ask you for a ruling. Say, “Allah gives you a ruling concerning the one leaving neither descendant nor ascendant as heir. If he dies leaving no child but a sister, she will get one half of the inheritance. Likewise, he will inherit her if she dies leaving behind no descendant. If they are two sisters, they will share two thirds of the inheritance. Should there be both male and female siblings, then the share of a male is equal to that of two females.” Allah explains it clearly so that you do not fall into error. And Allah is All-Knowing of everything