Referring to this topic above to Dr. Monzer Kahf, Scholar in Islamic Economics & Financial Expert, he said,

If the properties belong in fact to the deceased, then they must be distributed according to the Shari’ah in this case, assuming no other heirs. The wife gets 1/8 and the rest to children at the ratio of 2/1 male/female. If the deceased willed part of the property, his desires and instructions are invalid except within the one third and to non-heirs such as grandchildren who do not inherit otherwise.
But it has to be proven that these properties are in fact owned by the deceased not by whoever names appear on them.