ib- It is amazing how insightful kids can be. You should feel proud that she is able to see things pretty clearly at a young age.
I am not entirely familiar with your sitch so I'm not sure how much input I can give you. I think most MLCers are uncomfortable acknowledging anniversaries. IF, and that is a big IF, you do anything I would keep it very simple like a card that lets him know you are thinking of him.
I hope you are strong and make it through your anniversary as painlessly as possible.
