"I know!" she beamed (and I started preparing for a curve-ball..), "We could make a Chitty-Chitty-Bang-Bang cake!".....
We melted easter eggs (and we STILL have more of them!) and set the chocolate in a silicone mini-cupcake tray to make the wheels. We even made the spare wheel.
I strongly suggested which sweets should go where to make the cake look suitably vintage-car-like and the girls took turns in sticking them on.
All those things that I love about the way that communities of women work together were right there, in the embryonic stages of social skills.... and it seemed so natural. Beautiful!