"I don't pay attention to it and I wish she wouldn't have to," Carter said of the negative press surrounding the duchess. "I feel like there's just so much. It's just all too much."
"It must be really hard for her not to, but all I'd say to her is, as soon as you become well known and in the public, it's a domain you have to kind of accept. All that people think about you and write about you, that's about them and it's not really about her," she continued. "... The most important or useful thing that someone told me is [why are] you putting your self esteem in the hands of strangers?"
Carter went on to compare Markle's experience to things she learned while portraying the late princess on the Netflix series.
"That's the same thing with Margaret. It's really interesting playing her. So many people keep giving me an opinion about every single person in the royal [family]. You're like, 'You didn't meet them!'" Carter said. "Everyone feels that they're an authority. And of course, unless you've met the person, don't even voice an opinion."
Carter also recalled a funny story with another royal, Prince William. After a caller to the show asked how the Duke of Cambridge reacted when she asked him to be the godfather to her child, Carter shared the details of the encounter.
"I wasn't that drunk. Enough drunk for me not to drink any more. He wasn't totally sober himself. Not in a bad way, it was just very jolly," she said.
"The thing is, I'd spent all my friends as godparents on my first child, so Billy had 11 godparents. And so I thought I could make up for Nell -- who suddenly came along and we didn't have any left -- I thought, 'Well if I give her Prince William that will cover [everything],'" she said of her 16-year-old son and 11-year-old daughter with Tim Burton.
"He just said, 'You don't want me to be godfather to your child.' And I left," Carter added. "I mean obviously it didn't work out."
Season three of The Crownis now streaming on Netflix.