I think you should say you once studied a long time ago. That way she wont know you were ever involved and she wont be afraid to talk to you because you "know too much." Then you can tell her that the reason you stopped studying was because too many things didn't make sense. That will lead you into examples.
If anything, you could practice on her. YOu know, trying to feel her out and see if you can get her to THINK.
Unfortunatly, she's almost everything you'd expect out of a dub. A 32 YO unmarried woman, successful, but extremely chaste. You can't say shit or asshole around her. 'Fuck' is right out. She's kind of shy, attaches herself to attractive men, but never gets close. Reminds me of some of the eternal virgins I once knew.
Ashi, if she's cute you can give her my number. I'll see how faithful she is to JW rules and let you know if it's safe.
Seriously, I like Prisca's (you can call me, too) suggestion. I always imagine being approached by Witnesses and using the "I have family that are JWs" line to explain how I know so much about their history and teachings.