The blame shifting is SOP among alcoholics and their enablers. You are a convenient target, being the ex. None of it can be her fault, because that might lead to uncomfortable realizations about her drinking. The family wants to stay in denial so they go along with it.
So sorry to hear that you suffered physical abuse. That is never OK, ever. You deserve much better.
You may never understand her or her family's distorted thinking, but you can understand yourself, find out what makes you tick, why you stayed so long for so much abuse (I am not criticizing you here, I did the same thing, stuck around WAAAY past the expiration date should have passed on my last relationship.
I've been working things out with Alanon and through individual counseling. You made a good, healthy choice for yourself. Nothing to feel guilty about.