Question
Is it normal for a 9 and a half-year-old girl to have her period?
Answer
Generally, girls start experiencing rapid growth spurts between the ages of 11 to 12. However, for girls who begin to grow taller rapidly at around 8 to 9 years old, with an annual increase of 7 to 8 centimeters and a weight close to 40 kilograms, their development may occur earlier. These girls might start breast development at 9 to 10 years old, whereas the normal age for this is around 11 years. Moreover, research shows that girls who start their menstrual cycle early usually have a bone age greater than their actual age. For instance, a girl who starts her period at 9.5 years old might already have a bone age of 13.3 years. In the student population, the rate of sexual maturation for individual girls often exceeds their age, and early puberty in girls is more common than in boys.