Division of inheritance among wife, 2 daughters, and one full-sister
31-12-2017 | IslamWeb
Question:
Assalaamu alaykum. Please calculate the inheritance according to the following information:
- Does the deceased have female relatives who are entitled to inherit: (A daughter) Number 2 (A wife) Number 1 (A full sister) Number 1 (A half sister [from the father]) Number 1
Answer:
All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad 
is His slave and Messenger.
If the heirs are only those mentioned in the question and the deceased did not leave any other heir, then his wife gets one eighth as her legal share due to the existence of the children (direct heirs); Allah says (what means): {But if you leave a child, then for them [i.e. the wives] is an eighth of what you leave, after any bequest you [may have] made or debt.} [Quran 4:12]
His two daughters get two thirds as their legal share, as it is confirmed that the Prophet gave the two daughters of Sa‘d ibn Ar-Rabee‘ two thirds. [Ahmad, Abu Daawood and At-Tirmithi]
Ibn Al-Munthir 
said, "The scholars agreed in a consensus that the two females get two thirds."
The remainder will be allotted to the full-sister by Ta‘seeb (by virtue of having a paternal relation with the deceased and not having an allotted share, so she gets what is left after the allotted shares have been distributed); as it is confirmed that the Prophet gave the sister what remained after the share of the daughter and the son's daughter was allotted. The hadeeth was reported by Al-Bukhaari from Huzayl ibn Shurahbeel.
It is for this reason that the scholars considered the sister as someone who takes whatever remains from the inheritance after each one has taken their prescribed share.
The half-sister from the father’s side does not get anything from the inheritance because she is prevented by the existence of the full-sister.
Therefore, the inheritance should be divided into 24 shares, the wife gets one eighth, which is 3 shares; the two daughters get two thirds, which is 16 shares, each one of them gets 8 shares; the remainder, which is 5 shares, is for the full-sister.
Allah knows best.