Gather or borrow four to seven sets (depending on the number of groups you will divide your children into) of blocks of various kinds such as Lego, Lincoln Logs, Duplo, wood blocks, dominoes, sugar cubes, etc. Also, obtain a flat surface such as a piece of cardboard or cookie sheet for each group.
Create some paper "bricks" by writing the attributes needed to strengthen a family on pieces of colored paper (see discussion below). Leave some papers blank for any ideas the children come up with.
Divide the children into groups and give each group a set of blocks to build a house with and the flat surface for them to build it on. Set a certain amount of time for them to work on their house.
Invite each group to come to the front of the room and show the rest of the Primary their house. Have them briefly explain some of its features and why they built it the way they did.
After all the groups have shown their houses, talk about how each house was different. Explain that all our families are different too, but that they are all good.
Discuss how buildings are as strong as the bricks or materials used to build it. Ask the children what things we can do in our families to make them strong. Build a "brick" wall on the board with the paper bricks you made. Talk about each attribute as you have a child help you put that brick up on the wall. Possible bricks could be: Family prayer, Family scripture study, Family Home Evening, Family meal time, Attending church together, Working together, Playing together, and Discussing Sunday lessons after church.
Sing songs to reinforce the ideas taught such as "Love Is Spoken Here" (Children's Songbook, 190), "The Family" (CS, 194) or "Family Night" (CS, 195), "Happy Family" (CS, 198), "When We're Helping We're Happy" (CS, 198), and "When I Go to Church" (CS, 157).