I've just re-read this thread, and only just spotted that you moved from Ireland to the USA.
Yet you tell me not to move there.
May I ask you why you say that, and.....are you still there?
@LindyLou2020
I moved when I was 23, back in 1988. I was young enough, as your daughter is young enough, to have time to settle in and get to know people, establish an adult life here. Sadly, my marriage to an American didn't last, but my children are American and their lives and friends and jobs are here. I'm 57 and have spent more than half my life here. I have seen my children's American childhoods and their passage through high school and on to university. I have lived all of that with them, learning on the hop. It's not like watching it all in a movie.
Even when talking to my children about Ireland, I have to fill in background information - Dublin is the capital, it's on the east coast, there are about a million people living there, there's a decent public transport system, people go on holidays ("holidays means vacation") to Spain and the Mediterranean region because Irish weather is damp and chilly, the education system is very exam oriented... there's so much they don't know they don't know.
You're like my children. There's so much you don't know you don't know about America.
I'm going to assume you are a lot older now than I was in 1988. Your entire life has taken place in the UK. You are not familiar with the old TV shows, jokes, songs, sports and other points of reference you would run into again and again in conversation as you tried to establish some common ground with people you met. You would have to try to connect with other people in the US all the same, and establish a life of your own independent of your daughter. You cannot just graft yourself onto the life she is creating for herself here. That would isolate you completely, which would be unfair to her and her husband. They're not responsible for you.
All the cultural capital you have now as a British person living in the UK would be completely useless to you in America. If you moved you would be starting again from scratch in early middle age with decades of catching up to do. It would be like burying your previous self and trying to become a new person, an American version of you, or a British expat version of you. Neither version would be fully You.
When chatting, people wold tell you how much they loved your quaint accent - you would be intensely conscious of it, and at the same time conscious deep down of how much of a gulf there was between you and the people you were trying to connect with. You've already noted the effusiveness of your daughter's in laws and how different that is from your life experiences. There's a lot more difference than just that between Americans and British.
I have friends who are Russian, a married couple who had professional careers in Soviet times and moved to the US in the mid 1990s. The husband got a job in IT, learned pretty good English, and tried his utmost to integrate, but there are elements of American life that completely baffled him and continue to be completely impenetrable. One big one is the sense of humour, which he doesn't understand at all, but there are thousands and thousands of small ones, little nuances of how people communicate with facial expressions, use - or non-use - of the eyes. The wife couldn't/ wouldn't make progress with English despite a previous career in academia.
It wasn't lack of brains that held her back; the culture shock was too much for her, and as she told me one day (in German, which I speak a little), she had to keep part of her Self completely intact or she would have felt completely lost in a spiritual, emotional, and psychological sense. So her world contracted significantly. They both live for their grandchildren, which is how Russian grandparents tend to be, regardless of where they live, but for the wife, family life (and a passion for cats) is all her life is. She misses Russia terribly. But she knows that she can't go back, because life moves on there too, and the Russia she knew doesn't exist any more. Someone else holds the position she had. Someone else lives in the house they lived in, grows vegetables in the garden they once tended. They go to a Ukrainian evangelical church once a month or so despite being atheists just so that they can enjoy the company of people who 'get' them.
You would feel completely detached from your own life, a stranger to yourself as much as a stranger to others, and painfully conscious of being completely foreign, if you moved. You can't bring your life, your full Self with you when you move to another land and into another culture in middle age or beyond. A huge amount of what makes you You would have to be jettisoned, or at least put into cold storage indefinitely.
To consider a move to America now is to contemplate a self-inflicted existential crisis.
I really, really urge you to read and re-read @Luredbyapomegranate's great post.