Wow, cypher, so festive! :-)
I liked your post a lot too.
One thing I'm thinking of doing is addressing that head-on. Something like, "You know we take promises seriously around here... one part of the Girl Scout promise is to serve God. What do you think that means?" Then can take it from there. I'd be fine with adjusting the definition as per Noddy -- serving the god within. 'Course, then she'll probably go around telling everyone she's God.
We'll see.