When my ds started walking at 11 months we got him measured for shoes at clarks who told us he was 4f. They told us he would need to be measured every six weeks as children outgrow their shows quite fast. However my son turns three next month and is still only a size 5F which means he has gone up only one size in nearky two years. I am worried about his growth. I am only 5foot 3 and his dad is 5 foot 6 so we are not tall people but my son just seems so much smaller than other children his age and he just does not seem to be growing. Is this normal??