*Btw in England we'd probably just call it "Proper English", or "The Queen's English", as opposed to "Oxford" - or it might just be "A posh accent".
Okay then, a few areas to note:
*Both EW, and PK grew up in sort of wealthy, middle class families, with well educated parents, doing good jobs.
*PK grew up in Surrey which is one of the most affluent counties in the country, and the sort of area where you would typically find that well spoken southern accent. EW moved to Oxford, also a very affluent area, at the age of five, where she will have, again, been around people with who spoke with that very proper manner. Before living in Oxford EW lived in France where her only English speaking influences would have been her well spoken parents.
*Both went through the private education system (Idk if you know what that is, because it might be different in the US, but in short its just schools you pay money to go to), and will have been continued to dvelop that manner of speaking through mixing with other well spoken children.
Accent isn't necessarily regional, but it location can have a slight effect. I live in the north, and you notice its more about affluence within a certain city that has a larger effect. For example I go to school on a rougher side of town, and the kids there speak with a much heavier accent to, my friends who I hang around with who live closer to me, in a slightly more middle class zone, who have just very regular accents, though none quite like Penelope's. But then you have to look at there background's as well, and the you look at here the parents are from, what school they're at, where they've lived...
There are some places, like maybe Liverpool, or Newcastle, where the accent is often upheld through nearly every class, though it will get deeper as it gets further into the working class areas.
