When my Uncle passed away unexpectedly last summer, the Pastor actually did a children's service/message at the memorial. He read the story: Waterbugs and Dragonflies by D. Stickney while the nieces, nephews, and grandchildren who were old enough (ages 4-12) sat up front. My daughter was 3 and we got a sitter for her all day. I had never heard the story before and I thought the Pastor had done an amazing job. I know it has taken a while for the whole idea to sink in for the kids. I mean until you experience the months following a passing you don't really understand "not coming back." Peace to your family!
Story:
http://www.rainbowsbridge.com/Belovedhearts/stories/Doris-WaterbugsandDragonflies-632617144169637500.aspx