Dear Prudence,My mother is about to turn 90, and one of my brothers is having a small dinner celebration. The problem is that I am estranged (for six years) from my other brother “Jim” for, I believe, very good reasons. My mother is laying on the guilt and the only thing she wants is for the family to be together. I understand her pain and I wish things were different, but they are not—I cannot let go of what really happened. I think I’m looking for some validation that my boundary is permissible?