So, first things first. What is a chav?
British slang, disparaging
"A young person in Britain of a type stereotypically known for engaging in aggressively loutish behaviour especially when in groups and for wearing flashy jewellery and athletic casual clothing (such as tracksuits and baseball caps)."
"She looked too chavvy and cheap on the first day of auditions," a source tells the Sun. "They want her to have a designer look with chic class—more Posh Spice than Vicky Pollard in Little Britain, which is how she has looked more than a few times."