Tahiri does not have much in the way of formal education. Like most post-ROTJ Jedi, she graduated cum laude from the School of Hard Knocks with a major in dealing with pain and a minor in dishing it out.
She lived with the Sand People on Tatooine until the age of nine, where she leared two things- how to speak Basic, and how to survive in the desert. Tahiri learned both of these from the Sand Person who adopted her. (Random aside: She speaks it far better than you would expect, seeing as she was taught by an alien who learned it late in life, over a few weeks, as a second language. But that's a discussion for another day.)
I'm going to take a wild stab in the dark here and say she didn't learn how to write Basic/Aurebesh until she was taken to the Jedi Acedemy- though since she and Anakin did the whole translating-Massassi-thing with the Golden Globe, she seems to do okay with picking up other languages.
While she knows how to count, add, subtract, multiply, divide, and do other basic math, she probably doesn't have a very firm grasp on anything more complicated than that.
What probably happened is once she got to the Jedi Acedemy on Yavin 4, she took remedial classes with Tionne or one of the other instructors to fill in the gaps. Since the GFFA is supposedly far more advanced than our puny Earth society, she would have learned a lot more than we would have, but in much less time. So most of it probably didn't stick very well.
Then you get into the matter of Riina Kwaad, the implanted Yuuzhan Vong personality. Riina was stuck in Tahiri's head fully formed from what I gather- childhood memories and all. Which I assume meant she got the equivalent of the Yuuzhan Vong public school system in addition to the remedial Jedi courses, so there's probably a healthy mix of conflicting information swirling around in her head. She'll do her best to draw on the human views, but when she can't remember that she'll whip out the Vong science.
In short? She wants to call a lot of things magic but she knows that there is more often than not a very logical and purely scientific explanation. She just doesn't know what that explanation is. She ain't got a lot of schoolin' besides in how to do Jedi tricks, but she's a fast and eager learner when something catches her interest.