The term “vacation” is generally used to refer to female menstruation, and it is possible that a 12-year-old girl who has her period once every two months may be normal, but it is also important to note whether it is a manifestation of ovarian disease or other illnesses. Generally speaking, the feedback regulation between hormones in the hypothalamus-pituitary-ovarian endocrine axis of adolescent females has not matured yet, and has not yet established a relatively stable menstrual cycle regulation, therefore, menstruation is relatively irregular, and there may be a manifestation of menstruation once every two months, which will gradually return to normal with the cycle of growth and development. There is no need to be overly nervous about this situation. It is also important to note that certain diseases such as ovarian tumors and hypothyroidism can also affect the menstrual cycle. In addition, it is important to be aware of whether the child is under stress from school, emotional fluctuations, fatigue, late nights or excessive exercise. It is recommended to consult a doctor if necessary.