On Christmas Eve, my husband's grandfather Norman died. Michael went to the funeral in Florida with his father, but my mother-in-law couldn't go because of a recent hip surgery. I told her I would bring the boys over the day of the funeral. She worried that they might get frightened if they saw her or my sister-in-law crying. I told her she didn't have to worry about that, because I had prepared them.
I don't believe in hiding death or mourning from my kids. Death doesn't have to be any more mysterious than it already is.