I think I was in 4th grade. Looking back at pics of myself as a child it makes me angry. I was mbl before that and a black neighbor informed by white mother that a relaxer would help with my dryness and make it healthier.
I've seen younger. My niece got her first relaxer at 5 I believe. She's 9 now and has since gone natural again.
If I ever have a daughter, she can do what she wants when she's 18, but until then she will be natural.