What share can be claimed by my stepmother in my father's property

My father married another woman after my mother expired when I was 3 years old and my sister 5 years old. Later on even my father expired when I was 10 years old. My stepmother got a partition from my dad’s brother and she entitled her name also in the registered partition deed when we were minors after that she was causing us troubles my sister got married in the age 19 due to stepmothers torture smehow i managed with my stepmother and i too got married a year before now I’m 27 years old. Now my stepmother claims she is entitled for half of the property and the other half is for me and my sister. This property is my ancestral property which was partitioned after my dad’s death between my dad’s brother and my stepmother and us. So what share does my stepmother get in property according to law