Shopaholic — Judy Waite

Taylor, Sam, and Sophie have been best mates forever. But lately things have been changing. Taylor is starting to sense that maybe Sam and Sophie would rather hang out only with each other rather than with her. And she can't talk to her mum about it -- she's been acting even more depressed than usual, spending the day watching the telly in her bathrobe and only eating when Taylor makes her dinner.
Then Taylor meets Kat while out shopping one day. Kat is glamorous. Kat is planning on becoming a model. Kat has dozens of older blokes following her around. And suddenly Taylor's life is looking brighter. Kat seems to understand exactly how Taylor feels and Taylor is willing to do anything to be friends with her. The thing is, Kat loves to go shopping and if Taylor wants to continue to be her friend, then she'll have to come up with the money to keep Kat happy...even if that means going against everything Taylor knows is right.
An emotionally-charged novel about what loneliness can drive you to do, and how a little credit card can lead to lots of trouble.