R.K.
You could have a people scavenger hunt. Make a list of questions about the older family members and the kids need to find who fits the question.
for instance:
1) find the person who served in WWII in the Pacific
2) find the person who is named after great grandma _____
3 find the person who saw The Beatles in concert
As the kids go around and ask questions they are also getting to know their elder relatives and a little about their lives. And as we all know elders love talking about their younger years.
You could hand out prizes for 1st and 2nd place. I would say a list of 20 questions. The prize could be a trophy or a book of Mc Donalds gift certificates.