Yeah, it just seems petty to whinge about her accent, which isn't exactly grating or that strong. The upper classes did travel a bit, so it's not surprising that many of them would marry those from the upper classes beyond these shores with accents to match.
Elizabeth McGovern is reasonable as an actress and is fine in this series, too. She played a minor role in The Wings of the Dove as the companion of Millie, a film that I enjoyed a lot, and she did OK in it, too.
Not a bad series, which has its moments, but it does feel a bit soapy at times. Still, it's a watcher and has kept me generally interested.