Pulp,
HUGE CONGRATS to your Grand Daughter, and you as well for helping to bring it all together for her.
My daughter started out trying to get one when she was 6, but it took a few years to come together for her at 9. She has been one it like a duck on a junebug ever since.
I now have three grandsons aging 3 - 10 and the oldest has done well since just before his 4th birthday, bagging hogs and a couple of nice deer as well. The middle one is hot on his heels but being a bit smaller build, he has a year or two to go before he can manage the rifle. Our deal is, you have to be able to hold and shoot the rifle by yourself, from which ever stand we're hunting at. So they get to shoot from a box blind, a double archery blind with a rail, and from off a bi-pod from the ground both sitting and prone. Sounds a bit much for a youngster, but the oldest blew through it like a tornado, the middle is having issues but we'll get through it. I think the youngest is going to take it to them all, in a year or two.
Like you, I have been very involved with the loads, instruction, and direction with them all. There is no finer reward than to see it all come together in a successful hunt.