Yes, skeletal structure is influenced by hormones. So the differences between male and female skeletal structures become more pronounced, prominent and conspicuously evident to the eye during and after the puberty that occurs in adolescence. But the DNA-determined and hormonally influenced differences between males and females skeletally and in many other ways are established in utero and in the months after birth.

Shortly after birth, humans go through a "mini puberty" whose occurrence and effects are profound but which have been largely ignored. In the first six months of life, male newborns for several months have testosterone levels as high as they will be at the peak of adolescent puberty. Female newborn humans have elevated estrogen levels during this time, but my understanding is that they do not reach the levels of female adolescent puberty.

The several months-long testosterone surge that male infants routinely experience in the first six months of life sets in motions many physical differences between the two sexes that only become glaringly obvious during and after the second puberty that occurs in adolescence.

Girls have the basic female pelvic structure from birth. During and after adolescent puberty, female hip shape becomes more pronounced and visible, in large part because of hormonally-induced weight gain and fat distribution.