Hello,
If an american female married to someone who is in the main eu block countries - say UK wishes to divorce will they lose she the C-Permit?

Thanks

NO - once it has been allocated you are removed from the quota list and only lose the C permit on leaving the country either voluntarily or through force... Also US enjoys the same conditions as EU anyway, well more or less.

A C-permit here is equivalent to a Green Card in the USA and just as in the USA - even if you got your Green Card through marriage, you don't loose it once you have it, even if you later get divorced.