What should I do about my daughter...?

My daughter is 12, and she's been reading "The Clique" series and she's turning into the main character Mie, who is a spoiled, rich girl and she goes to private school and has a clique called the "Pretty Committee". Anyway, my daughter is asking for a credit card, a bigger room, subscriptions to Vogue and CosmoGirl, she's trying to diet, and she bought a Prada bag with mine and my husband's money! And I let her have her friends sleep over one Friday a month (Mie's friends sleep over every friday) and she threw a huge fit. And now she's asking for a puppy because Mie has one, and I got a note from school saying she was bullying a new girl, and in the books, Mie bullies a new girl Claire. What should I do? She needs to be punished, I know but she seems to wiggle out of every punishment I give her, and my husband's a push over so he's not helping.