I remember back in 1970, the very first session with a T, and feeling like you describe and I told my story, etc. and at the end his only comment was "I didn't hear anything about your father" (my stepmother was my problem :-) and being horrified at the oversight.

What you say is always only about you as you are not those other people, your family. What you say is your point of view at all times and T's know that. When my stepmother died, I went around singing, "Ding dong, the witch is dead!" from the Wizard of Oz but that does not make my stepmother a witch or a bad person; that's just my perception and experience with her and that's what therapy is all about. I don't feel that way anymore (she died in 2001 and I finished therapy in 2005), our feelings and perceptions of our family do change over time and with therapy and that's not about them but about ourselves.