Generally speaking, a child’s IQ is somewhat hereditary, considering that a girl’s IQ is usually inherited from half of each parent. In reality, the IQ level of girls is related to genetic factors as well as to acquired factors. A child’s IQ is determined by genes, mainly focused on the X chromosome, which is higher than the Y chromosome in the gene sequence code, so the mother is more likely to influence the child’s intelligence, cognitive development, and other aspects. Girls have XX chromosomes and boys have XY chromosomes. If the child is a boy, intelligence is more influenced by the mother, while if the child is a girl, half is influenced by the mother and half is influenced by the father. Therefore, if the mother belongs to a group of people with low intelligence, such as congenital stupidity and schizophrenia, the child’s IQ will also be affected. However, the IQ of a girl cannot be determined by her genes alone. The development of IQ is usually also related to the family environment, educational environment, her own nutrition, and brain development. Therefore, a good growing environment is conducive to girls’ IQ development. Therefore, a girl’s IQ is only a basic IQ no matter who she inherits, but during the child’s growth, she should also give more nutrition to promote brain development and give a good educational environment, as every child has potential and cannot be judged by genetic factors alone. At the same time, during pregnancy, the mother needs to pay attention to reduce the stimulation of adverse factors, such as radiation, chemical substances, etc., so as not to affect the child’s development, resulting in low intelligence.