Ginny Weasley is a very powerful witch. She always has been, since before she was born. When she was still in the womb she had such an atmosphere of power that Molly Weasley had to stay in bed most of the time. The day she was born she demonstrated her magical ability by levitating herself out of the Mediwitch's hands. She had more gift than all the greatest wizards combined. A gift, but yet a curse at the same time. Voldemort knew of her power. The whole wizarding world did. No one spoke of it though. They said that the only way someone could have that much power was through dark magic, so they ignored it. Blocked it out so that, eventually, everyone forgot. Everyone but Voldemort. He knew that, one day, the girl would wonder why wierd things always happened to her and no one would be able to tell her but him. He knew that her forgotten power would be his found victory.
The day Ginny realized there was something odd about her was the day she started Hogwarts. By the end of the week she had felt so depressed, so disappointed, so crowded that when she discovered the Chamber she was glad to have a place to be alone and sing or write in her new diary. So far she hadn't had a chance to look into the diary, but that day when she opened the diary for the first time, it was like she had finally found the comfort she had been looking for. Tom knew and understood everything she had been going through. She had total faith in him, after all, he was helping her control her powers. She had always known, but never had she been able to control it before. Shortly after she found out the truth about who Tom really was and what he really wanted from her she stopped singing. It was like he had taken the life and all her power, just as he had been trying to do.
She was a completely different person after that, after all, you never come out of an experience unchanged. It wasn't until the summer after her sixth year that she found out just how changed she was. You see, when Voldemort was trying to take over her body he gave her some of his power in much the same way as he had given some to Harry only, since she already had so much power it molded into a new sort of power, a fire power...