She chooses what she believes, so you should get to choose what you believe.

Few if any "christians" are christian by the book. Everyone chooses what they do as prescribed by their religion. In what way does she want you to be more Christian?

Let me tell you what I'd do:
I would go to their church to see how they practice their religion
I would discuss my beliefs versus their beliefs, and inquire about some of the thought processes that she has about certain things she believes in (which it seems you've already done)

But
... if she asks you to do something that goes beyond just "trying harder" at being YOUR religion, and she withholds something (because believe it or not, she's "withholding" dating from you), it's a sign that she'll do something similar in the future
"no sex unless you go to church with me"

just my 2 cents~