These posts are really painful, not just because they're dredging up old memories and old hurts, but also because I am ashamed of how I treated my mother, the target parent. I apologise to her nearly every day and I hope that wherever she is, she can hear me (she passed away in 1996). I'm pretty sure she can. I, however, am still alive and still working through what happened to both of us and everyone else it affected.
I recently saw an aunt I haven't been in touch with for years, my mother's older sister. I told her about the alienation and asked what she knew about it. She said nobody had ever known. They - their siblings - knew something was wrong but not what. My mother kept things to herself a lot of the time. She was just a private person. Their brother said my mother didn't understand me. My aunt said, "If your mother had just said, "I don't know what to do with this kid anymore!", we'd have stepped in or talked to you or tried to find out what was wrong". This same aunt was present when my mother remarried - when I was hysterical that she was remarrying, feeling as if I'd failed to reunite the family because the male parent had made me feel it was my responsibility (at the ages of 7,8,9,10). She actually reprimanded me for my behaviour, telling me to behave myself and keep myself quiet on mum's special day. Even then, my behaviour was misunderstood.
It looked like I was just being horrible and bratty. I was actually a heartbroken ten year old, feeling she had failed her father and her family, realising that there was no hope of things going back to the way they were (which he had told me was how things should be, that their split was temporary, that she had just lost her mind for a while, that she didn't mean it, that she was being silly and stupid and stubborn, and was just being pushed into what her family wanted her to do, that she'd come to her senses) bearing in mind I could barely remember how things were.