A different way to think about how to keep the promise
Metallic or coloured card
print out of promise on circles that will fit in the middle of the star
string for hanging up
Make a star for every girl on metallic card (using template), stick the promise in the middle of stars, brownies to write on each point something to do to help keep promise.
Make little hole in one point and thread ribbon through to hang up with. They can either take them home or you could decorate your hut with them all.