A father has registered a will with the court that his property will be distributed among his four children (1 daughter and 3 sons). Now, after his death the sons are not giving the equal share of the property to sister but saying that they will give the share according to shariyat because it is not mentioned in the will that the share will be divided equally among four of them. So, I want to know that do the sons have the right to go against the will of their father? Father stated it verbally that the distribution will be done equally among the children but did not notarized in the will.
The daughter is a divorcee and a mother of a son who is studying.
Should she go to the court for her equal rights against her brothers? Actually, her cousins are also 3 brothers and a sister and they are dividing the share equally among themselves.

In Islamic Law, the girl receives half of what a boy receives. Hence, she must receive half of what her brothers receive. If the father wanted her to receive more, he can give her more from the 1/3 that he can give to any cause he wants.