How is the breast development of a middle school student considered normal?

Patient's question:

No

Doctor's answer:

The development of a girl's breasts varies greatly among individuals. Some girls begin breast development as early as 8 or 9 years old, while others may not start until they are 16 or older. Most girls begin breast development around the age of 9 to 14, before their first menstrual period. When breast development first begins, the milk ducts and surrounding fatty tissue form a small, button-like bump around the nipple and areola, causing the nipple and areola to protrude and the nipple to enlarge. Later, the protrusion of the nipple becomes more pronounced and gradually appears fuller, eventually developing into the shape of an adult breast. The speed of breast development also varies from person to person. Some girls may start breast development later but grow more quickly, while others may start earlier but develop more slowly.