No share giving in Will how can we claim it

We are two brother and 1 sister. My sister married before 30 years and living with her husband. My father wrote his will and his still alive, in his will they did not declare any share to my sister. they share all between among tow brother only. Now can my Sister or husband can file court case against my father or it can only be file by my sister only. Do my father has to give share against his will note. what happen if my father die (he is already crossed 87) in between. please advice