To be clear, I like MM and and I'm very glad she married Harry but if she's really started with the whole accent thing it's silly. I'm afraid it comes across as a bit "put upon" and fake to me. She should be proud of her own accent, it's perfectly nice.
People "adopting" accents because they think it makes them sound better is just one of those silly things that bug me. I'm very sure I'm being petty about it but it annoyed me when Madonna did it as well. It's one thing to naturally develop an accent over the years but she's barely been here five minutes!
www.thecut.com/2018/07/meghan-markle-british-accent-video.html