You could make flowers either with a single case or one inside another stuck to a popstick. Use glitter in the centre if you think it needs it. Or even some cotton balls glued into the centre.
I like the spider idea. You could hang the spiders with a bit of string so that they look like they are on a web.
Perhaps a lion - not sure how exactly except to draw the lion's body on cardboard and stick the 'mane' (cupcake case) to that. might be for the older kids.
Thread them onto string or wool with some cut up straws to make caterpillars. Not sure how long these would last tho!!
hope that helps - have fun
WA - gorgeous little girl