In any case, now that I have an anonymous presence far away from where my family is likely to stumble across it, at least I don't feel that I'm actually exposing anyone. I'm just talking about what I felt & what I experienced.
Often the people who tell me my threads are helpful note that they had quite different family relationships, so I don't think it's only about relating to the specifics... I suspect it's often about being allowed to think & talk about things that affected us deeply.