The height of a 9-year-old girl is 126cm, which is shorter than the standard height, but is generally not short, and it is recommended to keep observing and seek medical attention if necessary. According to the reference standard for children’s height, the standard height of a 9-year-old girl is 134cm, and a height below 128cm is shorter than the standard height, but it is generally not short. If the girl’s height growth is not less than 5cm per year, it is considered normal development. The child’s height is short, usually pay attention to take the child to participate in outdoor exercise, such as jumping high, jump rope, etc., to help height growth, usually try to do a balanced diet, eat more calcium-rich, high-protein food, with vegetables and fruits to supplement the nutrition, pay attention to let the child to ensure sufficient sleep, etc.. If you are worried about short height, or annual height growth is less than 5cm, you can take your child to the pediatric endocrinology department of the hospital to rule out growth hormone secretion and other diseases.