All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His Slave and Messenger.
Since the deceased did not leave any heirs except those mentioned, then his wife should be given one-eighth as a fixed share because of the existence of the children of the deceased. Allaah, The Exalted, says (what means): {… But if you leave a child, then for them is an eighth of what you leave, after any bequest you [may have] made or debt…}[Quran 4:12]
The daughters shall get two thirds of the inheritance as Allaah, The Exalted, says (what means): {…But if there are [only] daughters, two or more, for them is two thirds of one's estate...}[Quran 4:11]
The rest of the inheritance goes to the deceased's two full-sisters equally by Ta‘seeb (by virtue of having a paternal relation with the deceased and not having a prescribed share) because it was authentically reported that the Prophet gave the deceased's full sister the rest of the deceased's inheritance after giving the daughter and the son's daughter their fixed shares. The Hadeeth was reported on the authority of Huzayl ibn Shurahbeel and cited in Saheeh Al-Bukhari. Therefore, jurists considered the deceased's full sister as ‘Asabah (i.e. paternal relative entitled to inherit what remains after other heirs get their fixed shares) in this case.
Thus, the inheritance shall be divided into one hundred and forty four shares; the wife gets one-eighth, i.e. eighteen shares, the daughters get two-thirds, i.e. ninety six shares, each one gets thirty-two shares. The rest of the inheritance goes to the deceased's two full sisters, thirty shares; each gets fifteen shares.
Allaah Knows best.