Should kids attend funeral of a grandparent?

Yes: Well, it depends on the age of the child and whether they were close to the grandparent. If they didn't really know them, or are very young (too young to really understand) then no. However, children are oddly very accepting of life rituals, and they help the child come to grips with major life changes and move on. Be ready for a lot of questions though, and be honest.