Assalamualikum!
I am a Sunni Muslim. Besides following faraid rules in the distribution of one's estate, are there any other rules we can follow. I am a single woman, never married. I have three living sistesr and two brothers. Each have own family. I am rather intrested in giving my estaes to my nieces and nephews and to my sister.

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, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

The rulings of inheritance have been explained in details in the books of Sharee‘ah. If the questioner means by her saying, "I am rather interested in giving my estates to my nieces and nephews and to my sister," that she wants to make a will, it will not be correct to make a will for her sister because she is a legal heir. Making a will for a legal heir is not valid as previously clarified in Fatwa 85091. She is allowed to make a will in no more than one third of the estate for her nephews and nieces from her sisters since they are not legal heirs, and also for her nephews and nieces from her brothers if they are not legal heirs (i.e. if they were not prevented from inheritance with the existence of the brother). That is because making a will in one third of the estate for someone who is not a legal heir is permissible under the Sharee‘ah as we previously clarified in Fatwa 86417.

On the other hand, if the questioner means by her saying that she wants to give them a gift during her lifetime and she is not suffering from her death-sickness, this will be permissible unless her motive in doing so is to deprive some heirs of their legal right in the estate.

Allaah Knows best.