She definitely needs elocution lessons if you listen to her current advert. "It's like wa-er on my lips" and "a splash of shii" which creases us up because it sounds like "a splash of shi*e".
She doesn't have to lose her accent to speak well.
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.