The standard height of a 12-year-old girl is 152.4 cm. 12-year-old girls have already entered puberty, and to measure whether their height is standard, they need to measure their bone age, which is an orthopantomogram of the left wrist joint, to truly reflect whether their height is within the normal range. If the child’s bone age is closed, that is, the epiphysis is closed, there is no room for height growth. If the child’s height is within the normal range or almost the same as the height of the bone age, the child can grow to an average height of 160 cm in adulthood without intervention. At this time, if the epiphysis has not yet closed, parents need to hurry to treat the child’s height to avoid missing the critical period of height treatment.