It must be genetic. They are both fascinated by the sewing and design process. Making "patterns" and cutting their "fabric" and making their "clothes" out of paper. So I'm at my machine and B is sitting beside me with her scissors and a stack of paper and says "mommy, I made pants for my baby." Whoa, she really did. Crazy.
A side note - it took me two days to clean up from an afternoon of ignoring what they were doing to the house. But at least I got to sew.