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.
We ask Allah the Almighty to heal your sister.
If she passed away, then her wealth is divided among all her heirs according to the Sharee'ah division of inheritance, whether he was one who kept kinship ties with her or one who severed kinship ties with her, whether he helped her or did not help her, as negligence in the relationship of the inheritor during his life, and failure to fulfill his rights is not an impediment in Islamic law of inheritance. There are three impediments to inheritance: murder, slavery, and differences in religion. If these impediments are absent, depriving the heir just because he was negligent or severed kinship ties is not permissible. These sins are in the balance of his bad deeds, though. If Allah wills, He will punish him for them, and if Allah wills, He will forgive him, and Allah Almighty doesn't prevent him from inheriting because of them.
Allah knows best.