Nine year old girls begin to develop and it does not affect height growth. The average age of children’s puberty is between 10 and 12 years old. Regardless of boys and girls in puberty before the first one to two years of growth rate slightly slowed down, the girl 12 to 13 years old growth to reach the second peak of physical growth, at this time the average annual increase in the height of the girl 8 ~ 9cm. so, the girl 9 years old began to develop, will not affect the growth of height. In adolescence, must pay attention to the nutritional diet, to ensure that the child’s nutrient intake, give the child to eat more high-quality protein and fresh fruits and vegetables, suggest that the child to carry out reasonable exercise, and to ensure sufficient sleep, so that you can be strong and healthy, to ensure that the physical growth of the normal process.