I love these challenges! While I do not know who Tara B is, or Tara J., I wanted to weigh in.
Yes, what you suggested would most definitely count.
I do not know who would want "a perfect, white bloodline" or why it would matter, I would like to point out some obvious facts:
#1. By reading authentic history books (as opposed to those used in public schools and even colleges) one learns that way back when the Chinese hordes swept not only across Asia, but across all of Eastern Europe and parts of Western Europe.
#2. Whites are originally, for the most part, from Europe. (Mostly because there are albinos all over the world, Australia, Africa, etc. Also, the original natives of Japan were white!)
#3. Well, if whites lived in Europe and were run over by the Chinese hordes, that alone would ruin "a perfect, white bloodline".
#4. "Out of Africa" is only a theory, just the same as Darwinism. As no one has ever seen one animal species change into another species (or found any fossil evidence that proves it) no one has been able to prove that every one came out of Africa. To me, it doesn't matter, except it contradicts the Bible.
For years, those anthropologists claimed that everyone came out of Africa about 100,000 years ago (some claimed it was only 60,000 years ago). But when incontrivertible evidence pointed out that there were peoples living in caves in France more than 100,000 years ago, they changed their story to say that everyone came out of Africa 250,000 years ago!
No matter; as I say, it is only a theory, but it makes for interesting reading.
Now to your question: all she needs to do is to take a DNA test. I used www.familytreedna.com. Mine proves that ancestors did indeed come from China...and Japan, the Philippines, Polynesia, Australia, South America, American Indians, including Eskimos and Innuits, all over Europe, the Middle East, and, yes, Africa.
I am proud to be a mongrel; the royalty and purebreds are so stuffy.