So she was killed? Because she wouldn’t give him a divorce? Because she knew too much? If this were 50 years ago you might have a good case for murder, but how likely is that now, when divorce is more readily available? And RFK Jr. is pretty small potatoes. Whatever you could say about his father and uncles, it’s hard to see anyone being killed to save his pathetic little (non-)career.
Only until he launches his political career.
Did I say how or why she died? No. Her body was found hanging in a barn. Everything is pure supposition, including the stack of assumptions in your post.