WTF is a Jenovah's Witness ?

So, I moved to Netherlands recently for higher studies. And I met this girl from the US, and we have gotten quite close. We are not together but we have done all the stuff that needs to be done to be called bf/gf. Anyhow, she recently told me that she is a Jenovah's witness and that it is the reason why she can't see me anymore, over a fucking whatsapp text. I didn't know the term until today, and after googling some, I am more confused now than before.
I really liked this girl and I opened up to someone after quite a long period of lonesome time, last break-up really fucked me up. Now, she has completely ghosted me and I am just so confused.

I had known her for about a month, at first she was making the first moves: asking me out, planning dates and right after we got physical she got a bit weird, the sex was great but when I asked her about the satanic tattoo right above her ass, she just bummed out for a while and then gave a lame ass reply after abt 30 secs that her ex pulled a prank on her and she didnt know what she was getting at the time she got it she was drunk etc etc.
Things started going downhill from there onwards, she also acted very strange around Christmas, and the break up text was the day after Christmas.
I am a Muslim guy in my mid twenties, I have traveled more than many of my age and lived in many different continents,countries and cultures but I have never met a fucking Jenovah's Witness, so please any help would be really appreciated.

Idk, where else should I turn to, I don't want ask my friends as they might not know and it would be letting her secret out, so social media site like fb are not an option either.

Thanks in advance, and please dont ridicule me over this. Idk what to do, I have run out of options and I feel like I deserved more or at least a better explanation.....