Puberty events in girls are as follows:

• Growth spurt . Growth starts and ends earlier in girls than in boys. This growth spurt signals that a girl's menstrual cycle will begin in 6 months to 1 year. The growth of the trunk is delayed by one year in comparison to the arms and legs, so limbs appear awkward. Girls who experience their growth spurt earlier or later than others may need reassurance. Body weight and percentage of body fat also undergo changes in the developing adolescent.
• Development of breasts . Breast development continues for several years. Girls are often self-conscious and embarrassed, especially if (as commonly happens) one breast develops faster than the other.  
• Pubic hair . Pubic hair begins to grow at about the same time the growth spurt occurs.  
• Underarm and coarser body hair . This generally appears two years after pubic hair.
• Menstruation . The beginning of menstruation is called menarche . The first menstrual period usually occurs two years after breast development begins. A body weight of approximately 45-50 kg (103-109 lbs) generally signals both menarche and the end of the growth spurt. For menarche to continue, the fat percentage of the girl's total body weight must be around 17%.