oneounceload, you forget the leverage factor. You don't have to generate 95 pounds of force to knock over a standing 95-pound person. You just have to rapidly displace the upper part of their body from directly over their legs. A 12 gauge on a 10 year old's frame can easily do that. A 10 year old typically lacks the physical size to roll their shoulder sufficiently to handle the recoil it's going to cause.
When I was in high school (almost 10 years ago at this point), a measly 5'8" at 150 pounds, I frequently knocked over or displaced 200+ pound 6+-footers who thought it was a good idea to mess with me by blocking my path. I simply threw my weight into my arm horizontally across their chest and quickly walked by. They learned quickly that, short of an outright physical altercation that would attract all the wrong attention, they weren't going to stop me from coming through. In the future, a stern warning that, if they didn't let me by, I was coming right through them was generally enough.