I think your doing the best you can in your situation. I gave up arguing JW issues years ago with my wife but like you I slip things in once and a while. I wonder if you find it as hard as I do to figure out why they seem to allow certain non jw things in their lives while seemingly holding firm to other things. I once got my wife to go to some lesbian friends house warming when I convinced her it would be like any other house warming not an orgy. She had a good time there. Like your aunts birthday party its hard to ask them why will they do this but not that without causing them to get defensive and maybe erasing any progress.
I find your comment about Mexican JWs in service interesting. That is who I mostly see out in service in my area. Maybe they take it more serious than the English speaking congregation. I do however notice that they do look just as miserable as any other group of JW out doing the work of the Watchtower.