Equal Share of Property

My old mother is the sole owner of the property. We are a Christian family. I have two sons, both adults (unmarried). I do not have any property, assets or savings. I live in my mother's house & we are looking after her. I have a brother and sister, both older than me, & they both have their own houses. My sister has a son & my brother a daughter, both adults & married. My sister has a grandson, my brother two grandsons. My query is in the event of my mother's natural death, what would be my position legally to claim an "equal share" of the property. I do not know the contents of my mother's will, as I did not bear witness to it, so it is cause for concern. At the time of the will being registered, I was not informed about it, so I have no clue the contents of the same & how it might impact me and my family. Am I entitled to an "equal share" of this property, and are the grandchildren entitled to a share? I am currently living in my mother's house. My concern is that since my siblings are not in a good trusting relationship with me, I just do not want my share taken away, I just wish that the shares are divided equally amongst my siblings (only after her natural death). To say in simple terms, all 3 siblings get an equal share after her natural death of my mother, this is what I mean without the complication of someone getting more or less.