Q: A woman died and left behind a son and some daughters.
She also left a foundling girl whom she brought up.
Upon distributing the mother's estate, the son gave the foundling girl the same share as a full daughter without consulting the other heirs. Some of them were not satisfied with this action, so he is asking about the legal ruling.
The foundling girl has no right to inherit from this mother. If one of the inheritors objects to this action, he must guarantee the right in which he disposed improperly because they have the right to full inheritance. If they give up their right, it will be a donation from them and what they demanded is considered their right which is proper to demand. (Part No. 16; Page No. 513) The foundling girl is a stranger to them, so she must wear Hijab (a head cover to the waist) in the presence of this mother's sons. However, if their mother suckled her according to the conditions of Shari`ah, she will be their foster-sister but she still would not have the right to inheritance. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.