My kids made two snowmen; one to represent their matrilineal ancestors and one to represent their patrilineal ancestors. Hey, we used those words, too! I simply explained that the word matrilineal indicated their string of mothers in the family tree and patrilineal their line of fathers. Once the kids could visualize it on the snowman, I think they better understood what I meant.
We started out with some white poster board, but plain white computer paper would work just as well. If, like me, your free-hand circles are awful, you will need some objects to trace. I used three different sizes of Pyrex bowl lids.
I wrote the names of each person under their photo and labeled how they were related to my son and daughter. The kids colored a little bow for the matrilineal snowman and a top hat for the patrilineal snowman.
We only did three generations, but you could easily go another generation or two back by making the snowman a little taller.