First Generation First
Heirlooms become heirlooms when family members pass them down to their children. When it comes to dividing up your valuable items, don't skip a generation and give things to your grandkids. Part of the value of an heirloom is taking possession of it with the knowledge that it will one day go to your children. Your grandkids will, presumably, be receiving items of interest from their parents someday which represent a unique aspect of their relationship. With a few exceptions, you should leave your heirlooms to the very next generation.