Merck Manual

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Milestones in Sexual Development
Milestones in Sexual Development

During puberty, sexual development occurs in a set sequence. However, when the changes begin and how quickly they occur vary from person to person. For girls, puberty begins around age 8 to 13 years and lasts about 4 years. The chart shows a typical sequence and normal range of development for the milestones of sexual development for girls and boys.