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The LW may wish to look for a book with "Toxic Parents" in the title. I forget the author's name. I read it years ago and found it helpful. Another good one is "The Dance of Anger". The author discusses how people try to control situations by triangulating--looks like her parents are doing that now with her children. (Obviously, there's more to the book than that but that one really stuck with me.)
Growing up with toxic parents ain't a lot of fun (or even just one toxic parent)--and I fully understand why the LW has tried to cut them from her life and the lives of her children. Perhaps what Cary meant when he said she needed help was that she may be better served if she find a way of recovering/healing from that traumatic background. But it's gotta start with her, not her parents. She alone can break the dysfunctional heritage for her children.
Cary, it does sound like the LW's "stuff" triggered your "stuff". We all have people and circumstances that we avoid because they bring up horrible memories and feelings. It happens, and I give you credit for acknowledging that and for acknowledging you don't feel you can help her.