I’d seriously answer her questions to the nest of your ability, or refer her to people who can actually answer her questions.
A huge reason why people raised in Orthodoxy reject religion altogether is that they had teachers who refused to answer their questions. I assume you teach limudei kodesh; your training may have included teaching the finer points of dikduk, hilkhot shabbat, etc., but more likely than not, you didn’t study sifrei machshava or the pratim of Jewish theology. This girl may benefit from a meeting with someone who is well-schooled in the fundamentals of emunah, since it seems she may not be convinced of the Torah’s veracity and whatnot.