All the grandfather’s property should be divided according to Sharee’ah
25-1-2010 | IslamWeb
Question:
Assalam,My father in law died and he wanted to complete his wishes but couldn't do it and he died but during his last days of life he conveyed his message to her wife & daughters. His Grandfather named all his property exclusive to my Father in law due some reason. With good intention, so he wants to handover some of his land to his brothers & Sisters which was not given earlier by his grand father. Even he conveyed to Wife & duaghters that this much of number square feet of land need to be handed over to them(his brother& Sisters) .When he was alive he divided his some of the property to his daughter name and some it was in his name itself. After his death all property belongs to him were divided as per Islam but we didn’t complete his wishses which was conveyed by him. Now my question is that, As per islam, Are Wife & Daughters are entitled to give the lands as per father wishes which was conveyed by him during his last days) or there is no compulsion on Wife&duaghters to fulfill his wishes.
Answer:
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.
First of all, you did not mention to us the reason why the grandfather wrote all his properties in the name of your father-in-law, and whether he had written this in his name when he was in good health or when he was in his death sickness, and whether he [grandfather] handed it over to him when he was alive or that the son [father-in-law] received it after his father died, because all these considerations affect the answer.
In any case, a father, in general, is obliged to be just between his daughters and sons when gifting them, and if he was not just then the gift becomes void according to the most correct opinion of the jurists 
and according to our Fatwa in Islamweb.
This gift becomes even voider if the father had written the properties in the name of the son but the son did not possess it until his father died, because, in this case, the writing takes the ruling of a will and the will to an heir is forbidden except with the consent of all the heirs.
In both cases, your father-in-law was entitled to his legal share only from the inheritance and whatever exceeded this, he was obliged to give it back to the other heirs of the grandfather whether or not your father-in-law made a will to this effect.
Finally, we advise you to take the matter to an Islamic court so that it would study the matter in all its aspects.
Allaah Knows best.