Actually, I do think there's a particular British cultural thing happening here. I'm also not from the UK, but I'm Irish, so not a million miles away culturally or 'developed country'-wise, and I did my postgrad in the UK. I'd have two quite similar 'bubbles' in both countries: lots of high earning professional women.
It is absolutely the case that quite a large number of the British women have chosen to go part time/step back from their careers after children in a way none of the Irish ones (or indeed most of the women from other countries I met studying in the UK) have done. I actually think its interesting in that I wonder if the ability to work part time may in fact be a hindrance than a positive thing.
So, I went back to work and my husband and I did 50%. of pick ups and drop offs, we chose to live quite centrally and close to our childcare to enable this, our careers have remained equally important and we both do 50/50 housework etc. There is much less provision or cultural acceptance for women in professional jobs to work part time here IME - which most people assume is quite anti-women. However, this is compared to: couples moving further out so the kids can have a bigger garden, wife dropping down to 3 days a week till kids are in school and doing all the pick-ups/drop offs, then deciding role is too demanding to be done part time so doing something else, which has happened with loads of British friends.
Obviously, you're talking about massive privilege to be able to make those choices - lots of people in both countries obviously don't have that option, can't even necessarily afford childcare or make it work, but like the OPI am 100% talking about women where it was a choice. And actually, DH and I aren't in fancy high paying jobs, we can just about cover the childcare years but we've both chosen the more 'vocational' roles over higher earning alternatives. I'm still totally ok with v high earning friends complaining about their careers because we all make different choices.
But I am interested in why, culturally, its so different. For example, I know a few v high-earning couples where both are at partner-in-city-law-firm level: the UK-based ones, the wife stepped back after kids, they moved far out of the city, etc etc. The Irish ones, they got a live in nanny and run their diaries with military precision. My male friends here have stepped up more childcare-wise because there's no other choice.
I do think OP. it sounds like there may be more going on than you realise. Its possible its less of a choice than you think, that her husband simply wasn't prepared to facilitate her working and that she sees you being successful and it hurts. You do talk about her with something like contempt. I'm not in either of your shoes - I'm working, but not in a long-hours very high-earning way, and I'm really happy with the compromises I make. I look at people I know both in your position, and your friends position, and neither of those choices appeals to me AT ALL, but I accept both than I'm v lucky and that different people want different things (and generally still get to moan about having a bad day). But what is really clear is that your friend obviously isn't happy, or I don't think she'd react the way she did.