Mates, Dates and Portobello Princesses by Cathy Hopkins (Mates, Dates #3)

Nesta has met the perfect good-looking, fun, sweet. But there are problems too. Simon's from a rich, upper-class background - with a lifestyle to match - and it's difficult for Nesta to keep up. And then there's Simon's friend Cressida. The ice queen. The Portobello Princess. Not one to give in, Nesta is determined to impress the new crowd, but finds herself out of her depth. Luckily she has Lucy and Izzie to help her reassess what really matters...