Our kids grew up at Oshkosh. We started attending before they were born, and our son is now 21 years old, while our daughter is 18. They know the AirVenture grounds like the backs of their hands, and have been roaming freely there since they turned 13.
Are you camping on the field? If so (and I hope you are -- you won't have seen AirVenture if you're staying off-site, trust me), it's a whole 'nuther level of adventure for kids. Our kids LOVE camping in the North 40 -- there is always something to see or do there. Just make sure your daughter knows about the "whirling Ginsu knives of death", and she'll be fine.
If she's like my daughter, she will love the Fly Mart. There, you can buy everything from an aircraft engine to earrings shaped like little C-172s. Make sure she has some of her own money to blow there.
The EAA Museum is a great change of pace after a few days in the heat. They have a section just for kids that she will enjoy. And by all means take her out to the Sea Plane Base. It's a 15 minute bus ride (the route is well-marked), and it's a whole different world out there. From relentless sunshine and heat, to 100-year old shade trees and water. We always try to hit their fish fry on Friday night -- their Walleye Pike plates are hard to beat.
Spend the money on a ride in the Tri-motor. I took my kids when they were about your daughter's age, and they still talk about it. It's a great way to see AirVenture from above.
If you want to spend all day in the sales buildings (A, B, C, and D), you may want to take her over to the Theater in the Woods, which isn't far away. Spread a blanket, give her a few coloring books, and plunk her down in the shade. You know her best -- she may not be mature enough to be alone that long -- but if you drag her through all the buildings, stopping to look at every aviation gizmo along the way, she won't be a happy camper for long.
If she's like my kids, she's been to a zillion air shows by now, and may not be all that excited with the afternoon performances. Be sure to take her to the night airshow, though -- it's unique enough to even keep my kids' attention, which is really saying something. (They barely glance skyward by Day 3, even with Sean D. corkscrewing straight at the ground...)
There is no sleeping late at OSH, at least not in the North 40. There are daily dawn departures, as the EAA photo ship is taking off with someone to catch the magic early morning lighting. You haven't heard an alarm clock, until you've had a B-25 thunder over your tent at 6:30 AM. Ahhhh, music to my ears.
My advice: Stay the week, and make it an annual tradition. You and your daughter will bond like none other in OSH, mostly because you are a different you when you're there. Oshkosh is a magical place that only exists for a brief few days every year, and every pilot deserves to experience it.
