Let's start with even more basic stuff...this thread's location. In the Practical section there is a subsection called Studying in Japan. Admin should move your post there, and you should read relevant links.
Otherwise, I agree with nice gaijin wholeheartedly. And why are you posting for your niece? No parents? Why can't she herself post?
And, we might also suggest coming here for a visit, simply because "beginning to love Japan" could be for misleading reasons. Do you know hers?