Thanks to Deb for submitting this idea!
Since the theme this year focuses on Eternal Families, I felt inspired to have a "family history unit".
We started by introducing Family History, and proxy work to the girls. The co-leader used the lesson in the Joseph Smith manual from a few weeks ago, and we talked about different ways of being sealed to our parents, i.e. born in covenant, sealed to your parents on earth, doing the work for others.
I purchased two large size piece puzzles (70 pieces-10x13 inches) and put the puzzles together then flipped them over so the back was up. I wrote out a family group sheet on one (I used my family, and on the other I drew out a family tree. I took the puzzles apart and put them back into the box. When it was time for the activity, I asked a leader (the Primary President) to hide some of the pieces from each puzzle around the room. Some were EXTREMELY obvious, one was deviously hard and the remaining puzzle pieces were jumbled together on the table.
We opened with a prayer and I asked one girl to braid her hair without bending her elbows. When she had difficulty, I asked her if there was anything she needed and she asked for help. One of the girls volunteered. We likened that to doing proxy work. We talked about how we needed to know who our relatives are so that we can make sure their work has been done.
Then I showed the girls a set of blank forms and explained to them that they would start with themselves and fill in the information for, and then they could ask questions about their parents and possibly grandparents. When they asked what about if they didn't know someone and we explained how we could ask others for information as well as use the internet (Family Search, Ancestry.com, the libraries, etc.) and showed them copies of some of the documents I had for my family.
I reviewed with them some of the information found in the forms and went over how no one document is going to have all of the answers but that that's when we have to put together the puzzle pieces and make sure they fit. We then started putting together the puzzles. They realized that some of the pieces were missing and I pointed out that sometimes you have to search very diligently. They started finding the pieces; some were hidden within the papers I'd brought in, some were scattered on the floor, some on the piano, the rostrum, chalk rails, heaters, window ledges, etc. The one really "devious" piece was hidden out of sight.
The girls assembled the puzzle by interviewing me (they asked me who had this last name or this birthdate). As the puzzles were near completion, they realized that they were still missing pieces. It finally became apparent they needed help from elsewhere, we likened this to prayer and being in tune with the holy ghost). The girls kept asking where could the piece be. The Primary President revealed the location in a still small voice.
This activity worked out EXTREMELY WELL.