There should I think be HK and China versions of the whole family. Although I actually am not sure the European babies have a HK version. I don't think they do.
Plus the NC ones that were mentioned, and they look more different because of their manufacture.
I am going to leave alone the debate as to whether all of those are Spanish made xD.
...There aren't really UK and US families though. The four part family was sold across Europe - Western Europe at the very least. Chinese and NC versions of the parents are more common in the UK, I can't speak for the other areas but imagine that the same is true. It's probably to do with timing of the releases.
Similarly, the "US" sets were sold quite widely - we even had them here as store imports in the box set format (otherwise they were sold loose on card).
If you are in the US you're more likely to have a HK or China adult, but that's all.
Pony distribution is really messy
but I think it's important to get away from these ideas of US and UK versions when neither one is actually true in about 95% of cases.