Sorry about the loss of your mom's sister, because I know you loved her, despite her terrible behavior. Sometimes it's really hard to forgive certain things. I will pray for you to be able to release that anger and wish her well on the Other Side.
I've asked God in the past to help me forgive, and then to "forget" painful things said to me. He WILL do that. :) God is good that way!
Yes, I do believe all is forgiven between folks on the Other Side. All our tears are wiped away, our sadness is gone, and we are surrounded by love, peace, and joy.
Whenever something is within God's will for you, ASK Him for it. He is more than willing to help! :)
God promises: "Ask and it will be given to you..."
I'm a big believer in premonitions, Peg, and I see no reason why we can't have ADC's before death. Perhaps she was thinking about you and the things she was sorry for doing "before" she passed? Maybe she was regretting she hadn't "made up" with you and the other injured persons she had hurt??
At any rate the pain and suffering she caused is over and done with -- nothing you can do to "fix it" now. Ask for God's peace that passes all understanding -- I can tell you that it IS REAL!
God bless you and give you the peace you are seeking.