The fact that there is such a thing as a "GodTube" makes me feel a little weird inside, but I'll let it fly for this moment.
My first (cynical) thought about the video--within the first minute or so--was concerned with whether the video was scripted or not. The more I watched, though, the less I cared about the scripting. It doesn't matter if the parents told this little girl to say these kind things about her brother or not.
What matters is the way her parents have shaped her to appreciate, tolerate, and love those that are "different." How many times have you met someone who is hyper-conscious about how they understand people different from them and then you come to understand that they are related to someone who is "different" ? This little girl will be a better human, a more faithful child of God, and minister in a completely unique way because of the relationship her parents have granted her to have with her brother.