Lizzy has already made it through to the arena round

Robert Pattinson‘s older sister Lizzy is reportedly set to audition for The X Factor judges.

The 31-year-old is already said to have impressed producers during the early rounds and will perform in front of Simon Cowell, Cheryl Cole, Mel B and Louis Walsh this weekend.

‘She blew them away with her husky, soulful vocals,’ says a source.

‘She’s different to usual X Factor contestants – she really stands out. She could go all the way.’

Lizzy has previously sung backing vocals for Rob‘s Twilight films and her vocals have appeared on chart hits including Milk & Sugar‘s Let The Sun Shine.

London-born Rob, 28, is due in the UK next week so there’s a chance he may be around to support Lizzy as she tries to impress the panel.

But it’s unlikely that the pretty blonde will invite him as she wants to be taken seriously as an artist in her own right.

‘She didn’t mention she was related to him to any judges or producers,’ the insider tells the Daily Mirror.

‘It’s important to her she does not fall into the trap of just becoming “Rob’s sister”.’

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Anna Duff