Is it normal for a ten-year-old girl to start developing significantly large breasts?

It is normal for a ten-year-old girl to begin developing significantly larger breasts. Modern girls generally have better nutrition, and at around age ten, girls typically enter the stage of puberty and begin to develop secondary sexual characteristics, which often results in noticeable breast development at this age. Female breast development usually starts between the ages of 9 and 11, signaling the beginning of puberty. During this time, hormonal secretion increases, leading to the emergence of secondary sexual characteristics. Breast development in a ten-year-old girl does not indicate precocious puberty; precocious puberty is defined as the onset of sexual development before the age of eight in girls. At the beginning of breast development, girls may experience bilateral breast tenderness and pain upon touch, followed by gradual enlargement of the breasts and areolas. As development progresses, their voice becomes higher and finer, skin becomes smoother, subcutaneous fat increases, and both weight and height gradually rise. Additionally, pubic hair and underarm hair begin to appear, and eventually menstruation will start.