She is just a well spoken middle class type. She has similar accent to Sienna Miller, Kate Winslet, Emma Thompson, Helen Mirram, Judi Dench and all the other well establish British actors.
None of them put their accents on, it is how they speak. It may have differed from their inital upbringing, but I'd imagine when your training/studying to be an actor, your accent phases out as you want to be versitle and you end up with a nice well spoken accent.
She doesn't bothere me in the slightest anyhow, big up the Brits is what I say!!
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Michelle - You need to get to 100 posts before you are allowed an Av