It seems like that early exposure might be a factor as epoh pointed out. We all know that no matter how carefully designed it, most of the structured learning environment in school won't fit and would be potentially problematic for a 4-year-old kid, let alone a highly sensitive one. Instead of focusing on school selection, how about pay attention to other things that are essential to smooth out any bumps along the way, such as pencil grip, social skills, resolving conflict positively, attention span, flexible thinking, reading fluency, vocabulary, abstraction and conceptualization skills, analogy and cause-effect, problem-solving skills, etc.
