She probably is a US citizen, and even if not, she would have something to contribute if she became one. Strangely enough, the US consists of people whose heritage is from all over the world. It's one of the strengths of the country that it can draw on that cultural heritage and diversity within its own citizens to better understand languages and other cultural matters when in pursuit of intelligence in other countries.
That's the way it's supposed to be, yes. Unfortunately our politicians long ago discovered that divide-and-conquer can easily be implemented by pitting various groups against each other while promising to protect each from the others. This is why the USA has a collective unhealthy obsession with group identity. It's always black vs. white, rich vs. poor, Muslim vs. Christian, homosexual vs. heterosexual, etc. etc. Individuality is given only lip service by comparison.
This malignant design has been sadly successful. It has one primary goal and one secondary goal. The secondary goal is to herd voters into blocs that can be reliabily depended upon to maintain the ridiculously high incumbency rate. The primary goal is to conceal the one true division: the ruling class vs. everyone else.
A country with a more homogeneous population has a big problem trying to understand the rest of the world.
We manage to have that problem despite our genetic diversity because we have so precious little diversity of philosophy and viewpoint. The decline of federalism and the establishment of a very powerful central government sealed the deal. Now we have lots of people who look different but think in the same way. Cosmetically that's great. In every other way it's more of the same old status quo.
Your bigoted attitude will discourage people from getting involved, and ultimately undermines the security of the country.
You'll find that average Americans tend to be much more provincial than, say, the average European. Mainstream Americans usually speak only one language and don't visit foreign countries nearly as often as mainstream Europeans.
You know what REALLY discourages people from getting involved? The inability of most people to hire lots of lawyers and lobbyists which, when the media so grossly fails to do its job, is the only way things actually get done in Washington.