Bottom line here is that sex before marriage is forbidden. This is a Bible teaching. Everyone can agree on that. The org seems to be taking a lot of shots on here when they are just upholding Bible teachings.
The world has changed a lot. This rule must seem ridiculous to a regular person. But this is what it is. And she signed up for this and so did you when you got involved with her. I understand the heart wants what the heart wants but she could have informed the elders about your relationship and stayed away from fornication before you got married.
With her pioneering and then behind closed doors doin this, it’s just hypocritical. And believe me I’m not here to judge her. She really must be torn. And I feel for her. I hope you both can come to the best decision for each of you.