A girl's physical development occurs gradually, propelled by hormones such as estrogen. While some girls may begin showing the physical changes associated with puberty around age 8, others may not start until around age 14. Puberty can continue until as late as age 19. When puberty ends, you or the young women in your life will have completed the transition from childhood to adulthood.
Preliminaries
Even before any physical development is visible, a girl's body will begin preparing itself for the changes associated with puberty. The production of hormones is underway, and the ovaries are growing larger. This preliminary stage can begin at any time between the ages of 8 and 12.
Breast Buds and Related Changes
The appearance of breast buds signals the beginning of puberty for many girls. These small, hard lumps (about the size of a nickel) may be sore, and one breast bud may appear before the other. Often, breast buds arrive around age 9 or 10, though their appearance may also come earlier or later. Around this same time, fine hair begins to appear on girls' underarms and pubic area, and more-active oil and sweat glands may begin producing acne. Height and weight may increase rapidly.
Pubic Hair
For most but not all girls, true pubic hair begins to appear after the breast buds do. It is usually sparse and straight at first but gradually becomes darker and coarser. This stage of puberty usually occurs sometime between ages 9 and 15. Around the same time, breasts start to fill in and hips start widening.
Menstruation
Girls sometimes worry about not being prepared for their period's arrival. You can never pinpoint the month or day, but in general, menstruation begins one to three years after the start of breast development. Knowing the age at which a girl's mother or older sisters began menstruating can help predict when a girl will hit that milestone. Initial menstrual periods are often light or irregular.
Later Developments
In the later years of puberty, pubic hair covers more of the lower abdomen and inner thighs. The nipple and aureole may protrude more from the rest of the breast. Menstruation and ovulation tend to occur on a more regular schedule. The height increase that occurred throughout puberty tapers off as girls approach their mature height.
