The full sister and the full brother inheritance cases..
The first case..
She deserves the half legally.
" إِنِ امْرُؤٌ هَلَكَ لَيْسَ لَهُ وَلَدٌ وَلَهُ أُخْتٌ فَلَهَا نِصْفُ مَا تَرَكَ"
" If a man dies, leaving no child but [only] a sister, she will have half of what he left."
The second case..
She inherits two-thirds legally if they are more than one sisters.
"فَإِن كَانَتَا اثْنَتَيْنِ فَلَهُمَا الثُّلُثَانِ مِمَّا تَرَكَ".
"But if there are two sisters [or more], they will have two-thirds of what he left".
The third case..
She inherits as an agnate relative when there's one relative at her same degree.
"وَإِن كَانُواْ إِخْوَةً رِّجَالاً وَنِسَاء فَلِلذَّكَرِ مِثْلُ حَظِّ الأُنثَيَيْنِ "النساء
"If there are both brothers and sisters, the male will have the share of two females."
The fourth case..
She inherits with agnate relative because there is a female descendant for the deceased; daughter or son's daughter, either one or more, as the prophet said, "the daughter inherits half and the son's daughter inherits the sixth, and the rest for the sister".
Exclusion..
The full sister is excluded (deprived), if there's male branch heir, and by the father..But there's an argue if she is excluded by the grandfather.
The parental sister and the parental brother inheritance cases...
The first case..
She deserves the half legally if she is one sister, and has no other full sisters.
"إن امْرُؤٌ هَلَكَ لَيْسَ لَهُ وَلَدٌ وَلَهُ أُخْتٌ فَلَهَا نِصْفُ مَا تَرَكَ "النساء.
" If a man dies, leaving no child but [only] a sister, she will have half of what he left".
The second case..
She inherits two-thirds if they are more than one.
فَإِن كَانَتَا اثْنَتَيْنِ فَلَهُمَا الثُّلُثَانِ مِمَّا تَرَكَ".
"
But if there are two sisters [or more], they will have two-thirds of what he left."
The third case..
She inherits the sixth legally if there's parental sister with the full sister, as the scholars agreed, and compared with the son's daughter and the bodily daughter...Ibn Fawzan...As in the Hadith " the daughter inherits the half, the son's daughter inherits the sixth and the rest is for the sister".
The fourth case..
The parental sister inherits with agnate relative if there is parental brother or more, any agnate relative in her degree.
" وَإِن كَانُواْ إِخْوَةً رِّجَالاً وَنِسَاء فَلِلذَّكَرِ مِثْلُ حَظِّ الأُنثَيَيْنِ "النساء.
"If there are both brothers and sisters, the male will have the share of two females".
The fifth case..
She inherits with agnate relative due to the existence of a female descendant heir, either daughter, or son's daughter how so ever low, one or more..As the prophet, peace be upon him, said: "the daughter inherits the half, the son's daughter inherits the sixth and the rest is for the sister".
The parental sister exclusion..
First..
The deprived exclusion..
1- the father's existence.
2- the existence of the male descendant heir.
3- the existence of the full brother.
4- the existence of two or more full sisters.
5- the existence of the female descendant heir with the full sister.