Batgirl, Catwoman, girls from x-men such as Rogue or Storm
A flamethrower.
There are many different things one can put in a party bag for a 6 year old girls birthday. Any handycraft materials are in favour of many girls that age. A build your own bracelet or a necklase kit, or even a grow your own flower-kit.
A good source to research 50th birthday ideas is Pinterest. You can find a wide variety of creative and inspirational ideas for parties, gifts, and activities to celebrate this milestone birthday. You can create a mood board, save pins, and get inspired by others' creative celebrations.
spice girls sugar girls the good girls connect 4 (or how ever many girls are in there)
a book of math, reading ,science or any more subjects and throw a suprise party about ima genius
You should plan a party around the interests/hobbies of the child. There isn't one answer that will decide what you should do. The child would be old enough to offer his or her input and ideas and it can really help you. At this age kids are often interested in planning their own party. If you are stuck for theme ideas, game ideas, food ideas and any other party ideas you should check out the related link. It has alot of great tips and ideas, you are sure to find something!
Bakugan is a game that nearly every young child plays and loves. It is loved by people almost any age. You should try that.
Try http://www.great-time-party-games.com/fun-party-games.html for some fun party game ideas for any occasion.
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No there is not any!!
Garden.com and partycentral.com are two sites that offer additional information on throwing a party in your garden. They offer tips, food ideas and table decoration ideas to make your party a success.