Thank you for bringing the conversation back to the OP 🙂
Miriam was actually North American as Mexico is part of North America. But I saw someone else say that Miriam was South American either in news articles or on the show itself, too. And yes, there are a lot of slim small young men in Mexico.
I went down a little rabbit hole on this and started watching the first episode of the show as I was curious what the gentleman pictured in the Grauniad article looked like 20 years ago, so in case anyone else was curious here it is
https://www.dailymotion.com/video/x8kscmq
It’s my opinion it’s the voices that usually seal the deal to give the game away if all the other things didn’t before that.