division of property after father's death

My father has been expired. He did not create any will.my mother is alive and we are 2 brothers and 3 sisters.property documents are on my father's name. Me, my mother and my brother want property division among three of us. My sisters do not have any objection if property will be divided among three of us.they are agree with this and do not want shate as all three are married.So, my questions are below. 1.will property be divided equally between three of us or is it my mother's choice that how much share she wants to give to her children.2. After division can we start making walls in our house as partitions(because this will be a mutual decision between 3 of us) or first do we need to get any legal documents. 3.if any legal documents required to make partitions in house then what are they?