For a right-brained learner, spelling typically is ready to be mastered during the 11 to 13 year stage. That’s because for most people, spelling comes in two years after reading mastery. Since reading often doesn’t happen for right-brained learners until 8 to 10 years old, this is one of several reasons why spelling is a later subject mastered by right-brained people. Please see The Natural Learning Development for Right-Brained Children for more details. Otherwise, here are additional posts on the subject:

All About Spelling