Desi,

With adults the safest dose is 3600 mg- 3800mg as far as I know, from several different doctors. I am on 3300 mg, and my neurologist is considering increasing it from there. I am 17 though, and an adults size and weight.

With a 12 year old, I believe, from what I have been told from a pediatric doctor, she would safely use 1800 mg. So, I think that there is still room to move, though you do have to take into consideration height and weight.

HTH!