I gained weight all over (boobs, bum, thighs, hips) but had a reasonably small belly/bump - had a boy. Am carrying exactly the same for this pregnancy, don't know sex though. Most of weight is also gained during the first half of pregnancy for me too. I think it's more related to the woman carrying the baby rather than the sex of the baby. I never understood how the presence of absence of a willy would make a women carry differently!