With any luck your cabin crew will be nice to your little girl, I especially love it when kids draw pictures for us. Most kids on flight seem perfectly entertained by that. When I was a kid I spent the whole time looking out of the window except for looking in awe at the crew doing the safety demo!
As long as YOU'RE not stressed out she probably won't be either, so don't hype it up too much, and I'm sure everything will be just wonderful and she'll have a great time.