The normal range of height for twelve-year-old girls is between 146-158.7cm, with an average height of 152.4cm, while the normal standard value for weight is between 34.05-49.53kg, with an average weight of 40.77kg. There are certain differences in height and weight between children, so there is no need to be too demanding, as long as they are within the normal range. The diet should be balanced and reasonable, with an appropriate intake of high-quality protein, such as yogurt, milk, eggs, fish, beef, etc., as well as more vegetables and fruits. Let your child play outdoor sports properly, which also helps your child grow up healthily.