Probably a bit of a later bloomer. Orpingtons tend to be more on the slow side to mature. And that comb is awfully pink.
The size of the dot isn't determined by sex. Female barred rocks have smaller white head spots because they can only have one barring gene. Males with two copies of the barring gene will have a larger head spot than females, but males with only one copy will look the same as females with one copy until the secondary sex characteristics start showing. Single barred males are also going to have darker plumage like female barred rocks. I'm not sure if/how single vs double barring affects leg color.
