Heres an idea for Annies room: 4 canvases, earth, water, wind, and fire. Something like this one could be the earth (maybe with laurel flowers or hemlock trees?, blue and white crayons from the top for rain, maybe with an umbrella girl. Fire would be a sunshine, with crayons in the center radiating out. Wind... a kite sillouette with white, light blue, light teal and purple horizontal streaks?
Different way of doing melted crayon art: Place crayons in a pattern or 'drawing' and then melt for more interesting shapes instead of the usual drip.