1) Confronting a personality-disordered person with their behavior rarely leads to the hoped-for results. The PD person has serious cognitive (thought) processing problems fused with their emotional disorders. That means they aren't thinking logically, rationally, and don't draw the conclusions you'd like them to draw. A confrontation traumatizes, shames, and enrages them. So it doesn't work as a strategy to receive remorse or compassion from them. It causes them to regress instantly and viciously retaliate. They aren't able to make the links you want them to make (i.e., their abuse was wrong and had negative consequences, so they should repair the damage).
2) A personality-disordered person regresses at the drop of a hat. They won't announce that this is happening. You'll see it in their immature, irrational behavior. Your mother may turn very quickly into an angry 2 year old. This is why the confronting rarely works. They retreat into regressed states which are quite primitive. Not much can be done with a person in this state.
3) This is incredibly difficult to accept, because we want more than anything for the PD parent to recognize that their behavior was abusive; show remorse; make attempts to repair the damage. They usually are unable to do any of these things to the extent needed.
This was posted by I think Bunny some weeks ago but I thought it might interest you.
Nassim