Another thing occurred to me which my midwife told me at the time: Sometimes ladies who have ample boobies find the baby doesn't drink for long periods. This is often because the milk ducts within the breasts are more deep-set (i.e. covered by a thicker layer of breast tissue) and the baby therefore has to suck the milk a greater distance which is tiring until he or she gets used to it and develops greater strength.

Smaller breasted ladies have their milk ducts nearer the surface and the baby finds it easier to draw the milk a shorter distance.