Thanks for the nice comments. I am a pretty proud dad.
As far as teaching your nephew how to shoot, I have some suggestions if you are interested. It was not luck that my daughter was able to make a 250 yd shot in the field. It just takes a little practice. I took her out and had her practice four or five times under "field conditions". Had her shoot off of a harris bipod (which is what she shot the oryx from) in a sitting position. She also practiced from a bog-pod tripod both sitting and standing. Kids learn fast and I believe any kid can be taught how to shoot off a bipod. I believe that the harris bipod works well for kids because it is attached to the gun. You need to find out what height is good for the kid but learn how to adjust it up or down quickly in the field based on slope. The kid needs to shoot off of it enough to know it needs to be adjusted and to be able to tell you if it needs to be moved. At least for my kids, they are not as steady off of a tripod that the gun is just sitting on. One thing I do is have the kids shoot at fresh targets at know ranges and evaluate each shot. If they can get nearly every single shot within four or five inches of where they aim at a given distance I consider that their hunting range.
By practicing I knew how far she could shoot accurately, both standing and sitting. More important, she had "made the shot" from the same position maybe 50 times so she was comfortable when she had the shot at the Oryx. We passed on an Oryx at 280 yards earlier in the day because we knew she was very accurate to 250 yds so we set that as the limit. I am pretty sure she could have made the 280 yd shot, but we had a limit of 250 and stuck to it.
I'm no expert, but I think taking a kid out and having them shoot off a bench isn't much help for hunting shots. I have four kids and have taught them all to shoot off of harris bipods. So far they have taken 3 pronghorns at ages 8,9 and 10, 1 bighorn sheep at 17 yo, 1 Ibex at 11 yo, and 2 oryx at 13 and 15 yo. All on public land draw tags except two of the pronghorns. Cumulatively they have missed one deer and have wounded no animals. They have never even nicked guts. All shots have been off the harris bipods, except the bighorn sheep which was taken laying down off a backpack rest. I bet your nephew can learn to shot off a bipod or tripod in 2 or 3 trips to the range...