Mrs. Jones - I've been in similar situations and I'm kind of torn. I think it's important to do what feels right for you at this point in time. And each family situation is unique. But there is another way to look at it.
Some years ago I refused to attend my parents' 50th anniversary because I was still too fragile and unable to cope with my toxic family. In a way I was shunning them. When they had their 55th, however, I did attend. I realized that I had reached the point in my recovery where I did not have to feel ambushed or uncomfortable. (Of course, my dad is not a JW and the functions include plenty of non-believers.) In retrospect, that was the point where I started to restore relationships with my parents, and was able to enjoy a few years before my mom died. So I'm glad I made the decision I did.
But I've started to reason that I have nothing to hide. If I attend, in a way I'm showing them that even though I am "apostate" (their definition) and a "practicer of sin" I'm still the same person they always knew. I'm a good, moral person and my children are the same. I'm proud to show them who I am now. I let them know that I'm happy with my life and doing well (even if it's not particularly true!). I'm not blatant in any way nor do I create any confrontations. I just hold my head high and show them that even if they choose to shun me, I don't care anymore because they have no power over me. It's their loss, not mine. Surprisingly, most JWs are very nice and accepting to me at these things, including most of my family. It's my chance to show them that I'm not "mentally diseased" simply because I no longer follow their beliefs.
It's stil not a walk in the park, of course. As I mentioned on another thread, I wept through my nephew's wedding reception because of that profound sense of loss, the anger at what the Society stole from me and my daughters. But overall it feels good to have reached the point where I can attend these things without fear. If I choose not to attend, it's simply because I don't enjoy being around all those JWs, as we have very little in common. When I do choose to attend, my attitude is: accept me as I am because I'm worth it.