I have a feeling that women down the ages who had little pretensions to fashion and beauty have styled their hair in a similar way- such styles are virtually timeless.

generally speaking mthe hairstyles in P&P2 are accurate. They are modelled after contemporary drawings and portraits, and some of them are illustrated along with the original drawings in the book The Making of P&P . I don't have anything to show that Charlotte's was created from an accurate reconstruction of a genuine hairstyle, but I don't think there's any reason to assume it was not.

I agree it's ugly, though. She's a far prettier actress than she might seem to be.