Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
Though your in-law has the right, Islamically and legally, to distribute her estate while she is alive, she is advised to make a share for her father.
In his response to your question, Prof. Dr. Monzer Kahf, Professor of Islamic Finance and Economics at Qatar Faculty of Islamic Studies, states:
From the legality point of view, according to the Shari`ah, she can do whatever she likes with her property as long as she is alive and capacitated.
Potential heirs have no right and cannot limit a person’s actions. Also from legality’s point of view, if she was born out of wedlock, her wedlock father cannot inherit her because of lack of formal marriage (such a child has inheritance mutual relation with her/his physical mother only).
But from good-relation and kindness to father, it would be better for her to make a will to give him part of her estate when she dies (as he is not qualified as an heir).
It might be advisable that if she decides to give the property to your daughter and her cousin that she may consider giving a part to her father.
With regard to preventing them from selling, the condition of no sale in a gift is not permissible and not valid in the Shari`ah because that is an interference with an owner’s basic human rights.
Almighty Allah knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.