An Echo

First, I would like to point out how amazing of a person Lucy is. Lucy is so far away from her home, which was exactly what she wanted to be away from, yet she still misses it and almost everything she mentions about her new home with Mariah and Lewis reminds her of home. I don't think I would ever be able to be that far, with no contact (even by choice), knowing I can't go back.
Next, I would like to bring up my favorite quote in the whole book. On page 36, Lucy confesses, "I had come to feel that my mother's love for me was designed solely to make me into an echo of her; and I didn't know why, but I felt that I would rather be dead than become just an echo of someone." This quote struck me because for me, it brings together one of the main themes in the book, the relationship between Lucy and her mother. Even though Lucy is so far away and has no other contact with her mother other than the letters her mother sends (which Lucy never even opens), her mother has such a large influence on Lucy's life.
As can be seen in this quote, Lucy does not want to be like her mother or anyone else for that matter. She seems to be very much an individual, as is Peggy, which is why I think they became friends and why they remained friends throughout the book. Lucy also continuously mentioned how people tell her she is exactly like her mother, and while she refuses it in words, on the inside she knows that it is true. That is why I love this quote, I could just hear her saying it with doubt in her mind about how she would rather die than be like anyone else, yet at the same time realizes that is exactly what she is.
Does anyone else see the relationship between Lucy and her mother as being a main theme in this book? What other themes are there?