The only way that you can keep her from getting a dime would be if everything was put pod and tod to you and your brother. I can understand why you feel like you do and I don't blame you
Ancient history now, dad died in 2006, his will stated that it was to be divided equally between his 4 kids, and his wishes were respected.
My mom has remarried and her husband has kids as well, who are also very difficult to get along with, so I fully expect more problems then.
