Hello Southern,
Let me begin by saying that there is no such thing as “unforgivable.” While we may have been wronged to the ultimate degree, it is we alone who hold the power of decision as to whether or not to forgive someone. Now, let’s go a bit further into your question. Your “real” question here is not “how do I forgive,”… it is, “why did she do this to us?”
You do not specify who “she” is. You only give the impression that she is now deceased. I am assuming that “she” was in some way a family member… mother, sister, cousin, in-law, etc., or possibly an old girlfriend. In either case, the list of “why” she would do so much harm to you and your family could be endless.
It could be as she said, and just be a very poor attempt at mischievous humor by someone with no judgment. However, if the things she did were very exacting…very detailed in planning, then these things were not simply calculated to be wicked pranks.
The first thing that really comes to my mind is that for whatever reason, this woman craved attention. She craved attention from you in such a large way that it did not matter whether it was positive or negative attention, as long as she got the attention, was noticed, or will be remembered. Another theory is that of jealousy. Was she jealous that you had family, success, and seemingly all that was good in life and she felt she got shafted in life?
Lastly, if nothing I have stated seems to fit thus far, it is very possible that she had some undiagnosed physical or mental condition that prompted her to behave and/or react in this way and simply used you as the target. Depression, bipolarism, alcoholism, drug addiction, child abuse, and even a chemical imbalance could cause her to act out against you.
In my own case, my oldest son was similar to your woman. He stole from the family, he lied, cheated, he was at times violent, and did everything in his power to cause the family to alienate him….yet my son was very family oriented also. He knew right from wrong and was very intelligent, but somehow could never control the wrong doing. He died by his own hand 4 years ago at age 30.
Since they, (your woman and my son,) are gone now, and we will never forget the pain and/or destruction they caused, the only thing we can do now is to file the memories away, try to rebuild what they have ruined for us, and forgive them. It will not be easy to forgive as to forgive requires acceptance, and to have acceptance, you must have some reasons to explain all the things done against you. This is not going to be easy, but it will get easier with time.
I would also suggest talking with a qualified counselor, minister, or doctor to help you understand, accept and forgive. If you do not get to the forgiveness stage, you will never be able to fully move forward and eventually will drive yourself crazy also. I hope this helps you.