I as well agree that the shots may have been over the top or side. I may just add that with it being a 410, you may wish to go to 6 shot over the 4's just for the added amount of pellets as to over all energy of less pellets.
I also fully agree with maybe trying to go to a 20ga if money and the youths experience and physical ability allows it. If cost is not an issue, try to find a youth 1100 or 11-87. For it is gas operated, less recoil, can add a youth stock, fits youngsters better. Put full stock back on later, same gun, more years to shoot it.