OK. There is this book that is part of the Suddenly Supernatural series. Title is School Spirit by Elizabeth Cody Kimmel. It just happens to be that Kat (the story is from her prespective) starts out as a regular kid. Her mother is a medium(someone who sees ghosts and communicates with them). But that is not the beginning of the story. The beginning of the story all happens that she and her partner, Shoshanna Longbarrow, have a project that has to be due soon. They were at Shoshanna's house studying. They were finished studying for the day and Shoshanna wanted Kat's address so they could study at Kat's house later. The next day at Kat's house, as usual Kat and Shoshanna were studying. Shoshanna complained that it was too cold in Kat's house. Then, a opera sounding lady voice came from upstairs. Shoshanna thought that Kat was hiding something. Kat did. Shoshanna just burst out of the house without saying a word. The next day at school, in the cafeteria, she saw a girl carrying her cello. Kat said in her mind, Cello Girl. That is as far as I got to so far. Hope you read and enjoy the book!~ E. L.
I got this image at http://www.barnesandnoble.com/