Breast development is usually the first noticeable sign of puberty in girls. About 15 percent of girls will develop pubic hair before breast development starts. The growth spurt begins. Pubic hair begins to appear, usually within 6 to 12 months after the start of breast development. Uterus and vagina, as well as labia and clitoris, increase in size.
Pubic hair is well established and breasts grow further.
Boys tend to enter puberty between the ages of 9 and 14, with the average age being 11 . They tend to grow most quickly between ages 12 and 15. The growth spurt of boys is usually about two years later than that of girls. Pubic hair appears, followed by underarm and facial hair. Voice deepens and may sometimes crack or break.