I can't offer much, but start with the very basics. Keep it to Christ, the incarnation, the resurrection, salvation/theosis, and the like.
Honestly, if she wants to know, I'd give her the Gospels of Luke and Mark, and be ready to answer the inevitable questions.
I personally like "God's Revelation to the Human Heart", the short book by Fr. Seraphim Rose. It is a beautiful explanation of the Christian life; although I don't know how it would play to someone with no Christian experience.
I would not even delve into matters of the Church at this point, especially for someone who does not even know who Christ is. After all, we are trying to convert hearts to Christ, not to the Church. And if Orthodoxy is her first exposure to Christianity, there is no sectarian debate to be had. The theology of the Church is important and must be discussed at some point, but I would not begin there by any means.