Just my two cents! Spelling has nothing to do with intelligence. My uncle has major dyslexia, and his iq is 150. You maybe just as smart as you child. When you have a LD it can make you feel very stupid. I think i may have an undiagnosed mild Ld my self. I frequently find myself on the verge of tears when i can't do something simple(ex. putting something together from written directions, I must have a picture), yet i am more than capeble of advanced complex math and reasoning.
Don't sell yourself short!