I have to tell you... I know those evil thoughts of OP. I've had those too, but I have to say that finally I'm letting a lot of that go. I really feel she's in the past... and believe me I had a very VERY hard time letting that go. Even the feelings of revenge are fading. Boy, that's a relief! (I no longer have the urge to go to her work and pelt her with eggs!!!).
The fan sounds GREAT!!!!! Gosh, every so often you should go over there and program romantic and silly messages in it. Humor is always good!!!
One more thing to think about with temperament... are other people in her family like her? Consider how much could be biological. Studies have shown a huge amount of who we are is determined by genetics. Although I believe we can change, sometimes there is only so much and it takes huge effort. One has to be very determined to make changes and not all changes are possible. Do the people in her family (parents, older relatives) mellow with age? Things to consider...
There is no arriving, ever. It is all a continual becoming.