My mother passed away two years ago. There are six of us children. My one sister is named the trustee to her investment account. My mother told all of us to get the little metal box in her bedroom if she should die and that box contains all the paperwork for her investments. When cleaning out the house, that box was mssing. My sister is holding onto these investments and not paying them out to the siblings. I have reason to believe that she is spending the money herself. Do I have any legal rights?