First I couldn't understand the "Going South Thing about The breasts"..Now I understood, you folks mean" Gamayeey Hurddada Dheer"
That has nothing to do with breast feeding etc I saw a women who breast fed 13 kids and her breasts are like a 15 year old with firm well shaped breasts. It is mainly(90%) about their shape..Haven't you folks seen young girls with saggy breasts? It is the shape, the size etc
Yes when women get pregnant and have a baby their breasts gets bigger(Darar) at that time it is required to use a good bra..so that they don't sag...But believe me it is all about the shape..