The best way I found out to know if my DD is using I/R is for us to go and see javasource. :D
My DD is also12. We are on our fifth month since we switched from "forearm fire" to I/R with brush. Like you I'm not an expert and find my self never sure. If you can find a PC that teaches what is...
I feel like I could have wrote your post based on my DD who is 12...she's a lefty, small stature, low speed, 1.5 years pitching, #4 pitcher, etc. We have been going to a pitching coach who is at the high school and junior college level. She is good, not HE thankfully and got us where we are...