I know this song is overused, but I think it really shows how much pressure she was under throughout the third season of Sonic X. Her family had great expectations of her since she was the last child to be born from her mother's seeds, and so was their final hope. The Metarex used her to spy on Sonic and the others and she had no control over this, making her feel like a traitor. And naturally, she wanted to help Tails and the rest of her friends and not be a burden to them. I think she must have felt very lost and confused during her season, especially once she found out about the mistakes made by her mother and Lucas, so that's were the idea for this AMV came from.
The song is "Numb" by Linkin Park