Embrace boredom. You are not responsible for all the fun.
Seriously, the coolest games, inventions, creations, home-wrecking destructo-weapons of doom -- they always come from boredom. So the next time the kid whines, "I'm bored," answer with "Great!" and then grab a cup of coffee. (See also: Don't negotiate with terrorists or open Pandora's box.)
Get outside. Even if you have to lock the door behind her.
Go to the library. Better yet, drop her off. (See also: Grab more coffee.)
Make something cool together. Let her wield the tools.
Invest in squirt guns, water balloons, and kiddie pools.
Don't take over chores. If the results are not to your liking, she needs to do more of them more often.
Ride bikes. Build jumps. Play until the streetlights come on.
Teach her kick the can, hide-and-seek, bloody murder, and then invite all her friends over and leave them alone.
Never pass up a kid's lemonade stand without buying. Never.
Make your own lemonade stand.
Buy cleaning supplies. Show her how to use them all.
Make your own ice cream. Eat the salt.
Let her run to the corner store for candy.
Don't freak out about camps. She'll be fine.
Go on picnics.
Read together. Read near each other, preferably with hot cocoa. (See also: coffee.)
Make a matching set of super hero capes. Do all the winning.
Cuddle on the couch with a good movie.
Watch as much How It's Made as she likes.
Have fun. And let her have fun without you.