Just seen this interview with her
She speaks much better English than Ray Winstone and he has become one of the UK's biggest actors. I recently saw an interview with Winstone and I couldn't believe an actor had such poor spoken grammar. It seems to be OK to speak badly if you're from London (EastEnders is another example) but not if you're from further north.
Cheryl's what I class as a well spoken Geordie in that interview. Her 'o' in words are sounding different. They aren't flat any more. Also, saying 'I' instead of 'a'. Saying me instead of 'urz'. Still, I suppose you'd have to clean up the way you talk for television. If they took someone from here whose speech hadn't been changed, you'd likely need a translator.