Breast development in puberty may begin as early as 6 years of age. Stage 1 refers to the normal breast appearance prior to puberty -- that is, the presence of just a slightly raised nipple. With stage 2 comes breast budding, or elevation of the breast and nipple from the chest -- the first sign of puberty in 90 percent of girls, according to an August article in "BMC Womens Health. While the ring of color around the center of the nipple -- called the areola -- may begin to widen in stage 2, further enlargement of the breast and areola occurs in stage 3. Breasts take on a conelike shape, and the areola may both enlarge and darken.