In case anybody thought I was kidding about my daughter nearly falling out of the tree from nearly 20 feet up, my wife got a pretty good picture of the kid.
You can see, near the bottom right, Morgan standing near Nancy's dad. He's probably 5'9" and Emma's way above him. Nancy has a couple more pictures on her blog too, including a close up. Even more impressive is that she's doing this in mittens and snow boots.