We just found out that my aunt died last year from my mother's other sister. This half sister of my mother asked my mom to give up her right for the inheritance. They all inherited something from my grandfather when he passed away more than 50 years ago. This deceased aunt never married, and had no children. How do I make sure my mom get her fair share of family estate/money, and how do we get her sister's death certificate so that we can proceed overseas estate/money also in a just way.