Well as with most things you accuse Americans of ....the origin is back in good old Pomerania:
"But you know what? "Gotten" is British. Just like other supposedly American words, like "garbage". We’ve just stopped using it, that’s all.
The word dates back to the Middle Ages, actually. While UK English-speakers phased it out over time, Americans kept it going and gave it nuances we Brits don’t perhaps realise. We tend to think of "gotten" as the equivalent past participle form of our "got". But it appears to be more subtle than that."
Hope that helps. I said English girls are painted and tend to be horsey. I stand by that, far too much make up. And the 'horsey" comment is pretty common in the RSA and USA. I think it derives from certain facial types and disastrous dental work.
But you said our girls are "mannish". Which I have never heard before.....what's your justification for the comment?