Why should she try to sound like something which she probably isn't and may not even want to be? Oh - and define 'cultured'. Is that just a posh accent? If so, anyone from Made in Chelsea qualifies, but from my limited exposure to them, most of them are idiots. Idiots with loads of money, but still idiots.
I don't sound posh, not want her too, just a legible accent would be fine.
You have clearly confused good pronunciation and communication skills with having a posh accent