At 11.8 years of age, girls can still grow an average of 10 to 18 centimeters, depending on the individual. At 11.8 years of age, a girl’s epiphysis has not yet closed completely, and she is still in a period of growth and development, so she can still continue to grow taller, and she can still grow an average of 10 to 18 centimeters, but the exact extent of her height increase cannot be predicted. Height is affected by genetic and environmental factors, and height varies greatly from person to person. Adrenocortical hyperplasia, precocious puberty, hyperthyroidism, chromosomal abnormalities, pituitary tumors, cretinism and other diseases may lead to abnormal bone age or backward physical development, and it is recommended to improve the relevant examinations when necessary. In our life, we should pay attention to strengthening diet and nutrition, supplementing calcium appropriately, and adhering to outdoor exercise, which can help promote the absorption of calcium. At the same time, we should pay attention to maintain sufficient sleep and rest, which is conducive to the secretion of growth hormone.