She watches them.

She takes turns watching both of them. One year Damon the next year Stefan.

She knows it's wrong but their hers. Even though it didn't she like it she loved them both.

She sees Damon as someone shes never seen before. She knows it's because of her.

Stefan became like something she never wanted him to become and she actually feels bad.

She knows that if they ever see her again they would never forgive her. She knows that she ruined two of the most amazing people in her life.

She meets them again and it's amazing to see that they have changed so much but at the same time their the same people she met 100 years ago.

She fights with them and Elena so many times shes lost count. And then it happens.

Elena gave her the cure. She became human again. She loves it but she also hates it.

She loves that she can have a second chance at being human and make things right. She hates it because she isn't as powerful again.

Elena comes to hate Katherine all over again. She regrets giving her the cure. Elena starts to think she deserves the cure more.

At the end of the day Elena never chooses and runs away, Caroline and Klaus get married, Damon meets a girl who loves him for him, Stefan marries Rebekah, Elijah stays Elijah , Bonnie and Jeremy stay on the other side, and Katherine gets married to a nice loving man and has 3 children. One of which will make a line of family till the next doppelganger.

Kathrine dies at the age of 96 and has a small but sweet and loving funeral.

What no one sees is the many vampires watching from afar because even though she messed up their lives, they loved her for that.