Precious Bane by Mary Webb
Born at the time of Waterloo in the wild country of Shropshire, Prudence Sarn is a wild, passionate girl, cursed with a hare lip -- her 'precious bane'. Cursed for it, too, by the superstitious people amongst whom she lives. Prue loves two things: the remote countryside of her birth and, hopelessly, Kester Woodseaves, the weaver.
The tale of how Woodseaves gradually discerns Prue's true beauty is set against the tragic drama of Prue's brother, Gideon, a driven man who is out of harmony with the natural world.