There's a lot of confusion about England, UK, Britain, etc. Hell, it confuses me and I'm a Brit (whatever that is

).
For the benefit of those equally befuddled....
England, Wales, Scotland are separate countries (I'm avoiding concepts like principalities)
These three countries reside on Great Britain (the larger island that makes up the British Isles)
The British Isles includes Ireland, which is split into the Republic of Ireland and Northern Ireland.
The United Kingdom comprises England, Wales, Scotland and Northern Ireland.
Err...I think that is correct.
So, the waitress in the Rose and Crown could have come from Northern Ireland. Alternatively she could have come from the Republic of Ireland and Disney isn't too fussed that she strictly isn't a UK citizen.
Sorry if that has bored you rigid.