This is how I exposed my wife to JWD:
I waited until there was a topic posted that matched a conversation we just had about how boring and circular the meetings were. Mind you it was my wife's complaint. Lo and behold, a topic showed up on JWD and I showed it to her objectively. She read through it and initially thought I had orchestrated the whole thing. It did open her mind to the fact "apostates" are not all rabid destroyers. Some actually use a bit of finesse - like her husband.
If she asks how you found the site? Use my favourite excuse: Google News Alerts programmed with Jehovah* and Watchtower. This allows you third party access to JWD (even if it is not always trully the case).
Now if my wife catches me on JWD there is no lie or hiding, and I am free to occasionally point out a thing or two. Granted she does not know I am a posting member, but it did let me out from the shadows.