Please excuse me....I feel a need to put in a few words (OK rather more than a few!) on behalf of all my scores of American relatives (real Americans, not recent immigrants from Europe!), Americans who live in the UK and our American Tattlers.
I've spent a lot of time in the US, I've not once come across this 'massive culture clash' (and I've conversed with the widest range of Americans from the very top to people living on the street about Serious Things as well as more frivolously!).
Of course there are lots of differences between our nations and their respective cultures. I've been met with nothing but respect and admiration for the UK, together with some to a great deal of knowledge of our system of governance.
American children grow up very familiar with the concept of Kings and Queens, Princes and Princesses. Walt Disney and endless children's fairy tale books ensure that knowledge. In fact, that's exactly the same way British children learn about Royalty. It's actually not rocket science!!
Several of my professors throughout my long sojourn at uni were American , I got to know some of them well. We had great exchange student programmes and both Americans and Brits were respectfully curious and then enriched by each others' cultures.
Then we can look at all the other Americans who've moved to the UK - my Tacoma uncle (half native American) for instance, who loved the UK so much that he happily retired here with his family. From another side of my family, my dearest cousin from New England (an Indian by birth and a WW2 USN vet) who settled his family here. These people are just a few of hundreds of thousands of Americans from all walks of life who've successfully made their forever homes here.
There are numerous US celebrities who've made the UK their home without any compunction - famously Madonna and Tom Cruise (who, as we well know, even fell in love with the BRF!!). There's also one of Markle's SUITS 'co-stars' (I'd probably remember his name if he'd married a British Prince or Princess). I'm sure you can name many more US show biz emigres here.
More to the point, we can look at the many American women, commoners all, some actresses and others media personalities who've recently or in times past married into the British aristocracy (sort of Royalty Lite).
These women have made huge changes in their lifestyles very successfully whilst retaining their American identities and bringing their uniquely American characters, skills and know-how to their British families with very positive effect.
We could also note that several European Royal Families have equally welcomed mixed race and other foreigners to their families, most of whom have had to learn a new language as well as contend with 'The Culture Clash' - yep, at this point I'm getting mighty sceptical of this nonsense!
I honestly can't think of any American person I've known or met who would have made an adult, conscious decision to move to the UK to live and then viciously blown off our country because they couldn't adapt to our ways....
In my opinion, Markle's problem is that she wouldn't adapt. She refused to. She didn't want to learn about her new family and how the firm works, she blew off all the expert help she was offered. Any important new role or job demands that the new recruit applies themselves to a period of intense learning.
For quite a while this 'culture clash' palaver was cited in the UK media. But it emerged that the RF had (and still does have) American senior staff - all obviously very well able to 'adapt'.
It also emerged that, as far back as 2017 (before the Great Hollywood Celebrity Extravaganza at St George's), Markle was buying a raft of website domains with names that suggested she was planning to run for POTUS in each of the coming election years up to Doomsday! (actually, I think the most future year I saw was 2032).
And we know now that she retained all her US personnel (lawyers, manager, agent, yacht gig booker etc) and kept most of her clothes and domestic accoutrements somewhere in North America. It all suggests that she had no intention at all of integrating, doing the necessary work and making her forever home here.
Hundreds of millions of people have moved to new countries, the vast majority of us make a success of it in spite of sometimes huge differences in cultures.
So, with all the above in mind, I'm afraid I must gainsay PDina. I'm sure she's not intending to make excuses for Markle. But, really, she is letting her off the hook. (And I'm not even going to get into how easy it is to explain to Americans, in a way they can relate to, what our RF means to us).
Not only that, I strongly feel that PDina's ignoring and diminishing the integrity, intelligence, courage, good manners and achievements of all the many, many hundreds of thousands of Americans who've successfully made the UK their home. The UK is very much enriched by them in all sorts of ways.