I was enjoying this and having lived close to Jewish communities, I appreciate much of what you explained about Jewish people. I think you are getting a taste of how ingrained it is for some to make every discussion at least a bit contentious. Some are really "off" religious discussion, period. Others have come to their (current) understanding and can't hear any other explanation of a religious community without feeling challenged.
Of course some things touched me in certain visceral ways, too. That one can accept a larger commonality (,simply being born into a community) and being accepted for that accident of birth offends every fundamental/evangelical vestige from of christian(ish) upbringing that we have. As you know, JWs reject every festival and celebratory event they can other than weddings (which are not that fun, honestly) Getting to celebrate without buying into some belief system messes with our damaged JW brains sometimes. It's an entirely different view of the universe and the atheists will have at you on different levels altogether.
There are obviously Jews that probably give your understanding the side eye, too, but I quite enjoyed learning about your world view and hope you continue posting.
There are some lingering bits of being in a high control religion that might come back and bite this young lady in the butt someday. Encourage her and your nephew to educate themselves about it.
Good luck!