Inheritance

I want to know shares in iheritence according to sharia. My father had 2 wives, frst wife A had 3 sons and 1 daughter and the frst wife had passed away 60 years ago. Then my father married to my mother from whom he has 3 sons and 2 daughter. One son of wife A recently passed away a year ago who was not married at the time of death. Now please tell me whether the deceased's frst wife of my father will get her share or not in property. My father and my mother both are alive Alhamdulillah. Also tell me if my deceased step brother, who was not married, will get a share or not. Inheritence is of my grandfather who passed aaway a long time ago.