You should be aware that there is self-efficacy research on children as well as adults. In the research involving children, you can find studies by Barry Zimmerman.

Thanks Irvin!  Very helpful.

I found this interesting. It isn't quite what you wanted but shows the correlation between aspects of motivation and self efficacy. "Students motivation beliefs, self regulation strategies and mathematics achievement" Nikos Mousoulides nd George Philippou, Department of education, University of Cyprus.

 And I think Richard Ryan and Edward Deci have written at least anecdotally of the correlation.

Thanks Mark, I'll look into those!

Manz and Neck have a self-leadership assessment that includes self-efficacy.

Self efficacy is both a cause and an effect of performance--generally it goes up the better you do if there is feedback--SE also has causal effects separate from past performance--