I've been doing children's shows for a number of years. I might be able to give you a couple of ideas.
If you don't have a spring animal, get one! I use a Rocky Raccoon and when done right, it slays them! I even have Rocky find a chosen card.
Any large item levitation like Zombie is a definite must have. Kids love seeing something bigger than life happen right in front of thier eyes. I also start each show doing a borrowed item lev. ala Fearson Hookup.
broken and restored wand
sponge balls
Magic coloring book
PB&J
http://www.penguinmagic.com/product.php?ID=1051
Appearing/Disappearing crayons for coloring book.
The good thing is that if you don't currently do balloon animals, you needn't bother to learn. Many feel it's a requirement for kids shows, but most kid party magicians I know stay away from it and work all the time.
The age you are going to perform for is perfect! 7-10 yr olds have great energy, and when you perform well will reward you with exuberance and praise. They are also alot smarter than people give them credit for, so make sure your effects are flawless or they
will catch you.
I hope I've been of some help. Good luck with the show and have a great time!
