Not wanting to be a dick about it...
Absolutely not at all - on the contrary. I agree she should challenge things. One of my problems is she won't challenge her teacher at school, who went to great pains to explain the Christmas story and its relevance to her and her beliefs and is now doing the same with Easter. Now I get "because Mrs X said so" as a response.
I have always said to her I will not tell her what to believe (cards on the table: I am probably right on the line between atheism and agnosticism - I don't believe in a God, but haven't completely closed my mind to the possibility, however small I think that is, that there might be something more to what an awful lot of people believe ,even if it doesn't manifest itself in the same way that they believe it - it's just the majority of evidence that I have weighed up points to the no camp). It should be noted her maternal grandfather is also an ordained vicar in the Church of Wales - but mummy is not of the same opinion. But to explain my particular position and experiences and those of Mrs c00ps to a six year-old, doesn't exactly go very far at the moment.
tl:dr - You're not being one - but you already knew that