Life was so hard that she began to reflect on all the things that she had done previously. She had always thought that she was never wrong and everything that she did was justified and that she will always get away with it.
This is the reason why she had been so unruly and did so many things to make Arianna suffer when she was young until now. For her own selfishness she didn't even hesitate to try to kill Arianna when she was in a comma.
She wanted the other to disappear so badly, maybe that way she will no longer live in the shadows she had been trying her best to get away from. She never thought how Arianna's parents felt when their child almost died.
All she thought about was how the other was still living and why she wasn't dead yet. Why did Arianna had to have everything without asking when she was suffering like crazy?
