SASless,
While there are a few Boxheads in the Queen's genealogical closet, she's far from German.
Since the Brits are, by nature, a mongrel lot, most of us incline towards the thought that anyone born here, and who proclaims themselves English, sort of qualifies. And while Betty Windsor's grand-parents may have changed the family surname from Saxe Coburg Gotha as 'recently' as 1917, and though she's married to a Danish/Greek she hasn't got a German born ancestor since her Great great grandfather, Prince Albert (husband of the incredibly English Victoria - whose mum may also have been a tad on the German side), and we haven't had a foreign born or non English speaking monarch since George II, King from 1727-1760. That's nearly 300 years ago, and he was her great, great, great, great, great, great grandfather.
Not a terribly German monarchy..... and if we have to go back that far to define nationality, then there's barely such a thing as an American.
Generations:
QE II < KG VI < KG V < KE VII < Q V < Prince Edward, Duke of Kent < KG III < Frederick, PoW < King George II (who was a proper GERMAN - though in those days there was no such thing as Germany, of course!)