Ashley > Status Update

Can anyone help me find a book? I read this back in high school (pre 2009) and it was about a British band full of teens and their crazy lives and how when they came to tour in the US their band pretty much fell apart. It was sort of a "make it big" story and the rise and fame? I think there was a side character who was anorexic because of her mother? I might be confusing that by something else by the same author.