@DrWho
Best thing I could think of that you could do to help her wake up from the cult is to call her congregation, ask to speak to a couple of elders on the phone, they like to talk in pairs anyway.
Then share with them that she was putting pressure on you about the religion and you like her a lot, you've made out with heavy petting and fondling to the point of passion, ehem, but even though you like her a lot, you are not happy about the religious pressure and you want to get their understanding on whether she should be ok with just the relationship being sexually and emotionally involved, without bringing religion into it.
The fact that the elders know about her sexually charged encounters with you will start a process whereby she'll have to face up to the ugly side of the religion. It's like pulling back the curtain and seeing who the real Wizzard of Oz actually is.
Give her the jolt she needs. She is either going to reject you for not being a Witness or reject the Witnesses for forcing her to go against her sensual desires. Yeah, it may get ugly and she'll blame you for getting her in hot water with the elders, but if she's really that loyal to the Witnesses that's exactly the counsel she'd give to anyone else in her position.