I think we're almost there.
Humorously enough, I designed this bike from scratch, with great trepidation that I'd screw up and Bean would hate bikes, and his father, forever. Then I went and looked up the geometry on the Specialized Hotrock 12" (best kids bike you can buy, probably):
-ETT: 35cm vs... 35cm
-HTA: 70 deg vs... 68 deg (but see the note about fork offset)
-Chainstay length: 270mm vs... 280mm
-BB height: 173mm vs... 170mm
The Specialized runs a 5mm offset fork (vs ~20mm on the cheap threaded fork I have on Bean's whip) but the trail number is pretty close (50mm range for Bean, 57mm for Specialized).