Dede, many of us have done things in the name of "righteousness" because we were blinded by doctrine of a false religion. You can even look at the example of Paul in the bible who was zealously persecuting Christians. I think by what you stated, your mom forgave you and those last moments that you had with her were certainly better for her I'm sure.
I know that when I was a witness I would tell on people for doing things and would get on people for not contributing enough and I would look down on people for not being "spiritual". Looking back it makes me sick.