YES, you are fighting a lost cause, because her so-called "relationship" with you is based on DISHONESTY.
She has been dishonest with you,
she has been dishonest with her friends and family,
and she may have been dishonest, or unfaithful, to the vow she made when she ecame a baptized Jehovah's Witness.
You say the relationship between the two of you went from " a physical to a deeper relationship." I don't know what exactly you mean and I don't need to know. YOU know what you mean. SHE knows what you mean
SHE knows if she has already done things that could get her thrown out of her religion and her family.
YOU are not a JW. It is perfectly OK for YOU to communicate with me, but when you read this to her she will possibly have a fit or pass out. She might insist that you SHOULD NOT talk to me.
She wants to trap you in the same mind-control CULT that she is trapped in.
DON'T DO IT, MAN! Find yourself a nice normal girl who is not dishonest with you from the get-go.
Read this to her, and watch her reaction. THAT will tell you everything you need to know.
GOOD LUCK!