That State Machine you list above is a Jazz file, this one here: "asm_key">02d5df13:00000000:e91e77f2dfc4248a.
You can find that resource both in the SimulationFullBuild file and the ClientFullbuild0 file. Lift it out with Export to file and read it in an external program, an XML Editor or Notepad++ or whatever. If none of your programs will do it, Note Tab Lite will certainly do it, as it opens everything.
In there you will find the Posture Manifest or whatever it is you mention above, the "handedness" and all the other stuff.
The way I would probably go about attempting to place some animations on the child when they don't have any in vanilla game is to make a copy of this Jazz file, as opposed to typing in "Child" all over the place in the current file.
So I have the copy, which needs it's own Instance ID # to make it independent of the original, and presumably you can identify the new Jazz file in your modded XML by that asm_key, which lists your new file.
In the Jazz file itself, your new copy, all you need to do, I think, is replace all the actual Clip names themselves, for example clip=a2o_gardening_graft_low_x, with an appropriate c2o clip which is child-to-object, instead of a2o which is an adult-to-object Clip file. Simple.
There may be some other stuff which actually needs alteration in a new Jazz copy file which is intended for Child only, but this info can be gleaned and tested out by reading through one of the other Jazz files which are made for Child, like playing with the Monkey Bars would maybe be a good one to look at, as the Adults are locked out from the Monkey Bars IIRC?, so it's possible this Jazz file is written only for Child, and can be used for comparison purposes.
